Earlier, Russian state-operated media outlet Tass reported that the driver of a truck believed to be involved in the drone attack will be questioned by police.

Russia's defence ministry also says on Telegram that multiple participants in the operation had been arrested.

However, in his first statement since the drone operation took place, Ukrainian President Volodymyr Zelensky's says the people involved in preparing the major drone attack "were withdrawn from Russian territory in time".

Image source, UKRAINE PRESIDENTIAL PRESS SERVICE

Ukrainian President Volodymyr Zelensky has shared more details on the strike, saying 117 drones were used.

He says each drone had its own pilot.

"The most interesting thing - and we can already say this publicly - is that the 'office' of our operation on Russian territory was located right next to the FSB of Russia in one of their regions," an English translation of his post on Telegram reads. The FSB is Russia's security service.

He claims 34% of the cruise missile carriers at the targeted airfields were hit.

We're hearing from Ukraine's President Volodymyr Zelensky for the first time about the drone strikes.

He's just posted on social media calling today's operation "an absolutely brilliant result" and one "achieved solely by Ukraine".

"One year, six months, and nine days from the start of planning to effective execution," he continues. "Our most long-range operation. Our people involved in preparing the operation were withdrawn from Russian territory in time."

Zelensky says he met with the head of the the Security Service of Ukraine (SBU), Gen Vasyl Maliuk, and asked him to disclose the details and results of the operation to the public.

"Of course, not everything can be revealed at this moment, but these are Ukrainian actions that will undoubtedly be in history books," he adds.

"Ukraine is defending itself, and rightly so – we are doing everything to make Russia feel the need to end this war. Russia started this war, Russia must end it. Glory to Ukraine!"

Image source, Ukrainian Presidential Press Service

Vitaliy Shevchenko
Russia editor, BBC Monitoring

The Security Service of Ukraine (SBU) claims today’s attack on airfields in Russia has struck 34% of Russia’s strategic bombers capable of carrying cruise missiles.

In a post on social media, the SBU said its "Operation Spider's Web" cost Russia $7bn (£5.2bn).

"We’re doing all we can to drive the enemy from our land! We’ll strike them at sea, in the air and on land. If necessary, we’ll get them from underground," the SBU writes in a Telegram post.

Image source, SBU/Telegram

We're starting to see more reaction to Ukraine's drone attack on Russian airfields earlier today.

While the White House has not yet responded to the attack, the BBC's US partner, CBS, reports that the US government wasn't given a warning about the strikes.

An istration source tells CBS News that the Trump istration was not "aware that today's large-scale drone attack by Ukraine on the Russian military aircraft was coming".

Olga Malchevska
BBC News

A fifth of Ukrainian territory is now under Russian control, and for Ukrainians living under occupation there seems little chance that any future deal to end the war will change that.

Ukrainians in different Russian-controlled cities have told the BBC of the pressures they face, from being forced to accept a Russian port to the risks of carrying out small acts of resistance.

The potential dangers are the same, whether in Mariupol or Melitopol, seized by Russia in the full-scale invasion in 2022, or in Crimea which was annexed eight years before.

One woman, Mavka, says she chose to stay in Melitopol when the Russians invaded her city on 25 February 2022, "because it is unfair that someone can just come to my home and take it out".

In recent months she has noticed a ramping up of not only a strict policy of "Russification" in the city, but of an increased militarisation of all spheres of life, including in schools.

Meanwhile, children at nursery school in Crimea are told to sing the Russian anthem every morning, even the very youngest. All the teachers are Russian, most of them wives of soldiers who have moved in from Russia.

• Read more about life under Russian occupation

We're hearing a little from Ukrainians in Kyiv, who are responding to news of their country's massive drone strikes on Russian bombers earlier.

Speaking to the Reuters news agency, construction worker Pavlo Fesenko says: "I think it will have huge influence ... it can bring [Russia] back to reality and give us sort of a pause."

However, he doesn't think the strikes will translate into immediate results for Ukraine. "I do not think it will have influence we want it to be now. It is one of the steps that in future should lead to other talks where we should dictate ," Fesenko says.

He's hopeful that this summer will be Ukraine's "last war summer", he adds.

"I hope they will not have new miracle or new resources from nowhere and that they will finally fall. That is when we will have different talks on different ."

Footage showing several large aircraft on fire has been shown to the Reuters news agency by a Ukrainian security source.

Ukraine claims to have hit more than 40 Russian bombers, in what appears to be one of the most audacious attacks so far on Russian aviation.

The video shown to Reuters shows attacks on airfields in Russia's Irkutsk and Murmansk regions, an unnamed security official identified as one of the agency's anonymous sources says.

We're now seeing an update from Russia's Ministry of Defence acknowledging the strikes on airfields across five regions earlier today.

On Telegram, the ministry writes that Ukraine carried out what it said was a "terrorist attack" in the regions of Murmansk, Irkutsk, Ivanovo, Ryazan and Amur.

The ministry says that all of the attacks were "repelled".

It says: "As a result of the launch of FPV drones from the territory located in the immediate vicinity of airfields, several pieces of aviation equipment caught fire."

The fires have now been extinguished, it adds.

Russian state-operated media outlet Tass has reported that the driver of a truck believed to be involved in the drone attack will be questioned by police.

The report further adds that the "exact number of UAVs [drones] has not yet been counted", but says there is no threat to the public at this time.

Attack comes on eve of renewed talks between Moscow and Kyivpublished at 16:05 British Summer Time 1 June

16:05 BST 1 June

Hugo Bachega
Middle East correspondent, in Istanbul

Image source, EPA

Ukraine’s attacks happen as a second round of direct talks between Ukrainian and Russian officials is scheduled to happen in Istanbul on Monday. This is part of revived diplomatic efforts, spearheaded by US President Donald Trump, for a ceasefire deal – and, eventually, an end to the war.

Before the attacks, it was already very difficult to see any kind of breakthrough in these negotiations, given how far apart both sides remain in their conditions. Their first round of talks, on 16 May, reached little more than an agreement for a prisoner exchange.

On Sunday, President Volodymyr Zelensky listed Ukraine’s positions for the talks that included a complete and unconditional ceasefire, the release of prisoners and the return of abducted children. Russia, so far, has rejected calls for an unconditional ceasefire and repeatedly made demands that have already been rejected by Ukraine.

Ukraine also says Russia’s refusal to share its ahead of the talks is part of a strategy to delay the negotiations. Russia, meanwhile, has intensified its air attacks against Ukraine in recent weeks, and officials in Kyiv have warned that Moscow may be preparing a new summer offensive. This, Ukrainian officials say, show Russia is not interested in a ceasefire.

Both countries have reason to demonstrate to President Trump they his efforts for a deal: Ukraine wants more military aid from the US while Russia hopes the US will ease economic sanctions imposed on the country.

On social media a little earlier, Zelensky's chief of staff, Andriy Yermak, made an apparent comment about his country's massive drone operation.

Yermak posted an emoji of a spider web on both his Telegram channel and on X - seemingly a reference to the attack's name of "Operation Spider's Web".

Russia's major military assets shown to be vulnerablepublished at 15:29 British Summer Time 1 June

15:29 BST 1 June

Chris Partridge
BBC News weapons analyst

These attacks will have dealt a significant blow to Russia's aerial cruise missile strike capability.

Tu-95 bombers, which are among the type of aircraft that have been destroyed, are said to have launched a large-scale Kh-101 missile attack on Ukraine earlier this year. They have been used extensively since the full-scale invasion of February 2022 and so are a vital target for the Ukrainian military.

Each bomber can carry eight guided cruise missiles and each missile itself carries a 400kg (882lb) warhead. The weapons' range is thousands of kilometres, which allows such strategic aircraft to deploy well inside the relative safety of Russian airspace.

Image source, Getty Images

But just as significant is the reported loss of an A-50, the Russian equivalent of AWACS, whose role is to detect enemy aircraft and missiles, and feed those targets to Russian fighter jets. It performs a management role for aerial assets, by giving a big picture view and direction.

As for the strikes themselves, the use of drones in at least one, so close to the targets means that traditional Russian self-defence systems such as S-300 / S-400 long range SAMs, and even their shorter-range counterparts, Pantsir SA-22s, are ineffective. It also means that there was little warning that such an attack was coming to get aircraft to the relative safety of hardened shelters.

It may be that some of the Russian aircraft were not completely destroyed, and they can be repaired, but that still takes them - at the very least - out of the fight for a long time. More worrying for Moscow, it again points to the vulnerability of major military assets well inside Russian Federation territory itself.

Zelensky oversaw attack on Russian airbases, Ukrainian security sources saypublished at 15:14 British Summer Time 1 June

15:14 BST 1 June

Paul Adams
Diplomatic correspondent, reporting from Kyiv

Image source, Reuters

Astonishing details have been leaked to the media about how this morning’s Ukrainian attack on at least four Russian airbases was organised.

According to sources at the Security Service of Ukraine (SBU), “Operation Spider’s Web” took one year-and-a-half to organise and was personally overseen by Ukraine’s President Volodymyr Zelensky.

Sources say the SBU's first smuggled FPV drones into Russia, followed later by mobile wooden cabins.

Once on Russian territory, the drones were hidden under the roofs of these cabins, which had been placed on to trucks. At the time of the attack, the roofs were remotely opened, allowing the drones to take off and hit the nearby airbases.

Video has emerged showing drones emerging from the roof of one of the vehicles involved. Ukraine estimates the damage caused by the attacks at over $2bn (£1.5bn).

The targets hit included TU-95s (the large strategic bomber known as “Bear”), TU-22M3s (supersonic long-range bomber) and A-50 (early warning and control aircraft).

In a separate development Ukraine’s head of land forces, Maj Gen Mkyhailo Drapatyi, has tendered his resignation, following a Russian ballistic missile attack which hit a Ukrainian army training facility earlier today, in which 12 soldiers were killed.

We have some more from Irkutsk Governor Igor Kobzev, who has said that the drones that attacked the military base in Sredniy, in Siberia, were launched from a truck.

Kobzev posted on Telegram to say that the launch site had been secured and there was no threat to life.

Russian media outlets have also reported that other attacks were similarly started with drones emerging from the backs of lorries.

Let's recap some of the other developments from Russia and Ukraine in the last few hours.

• Russian investigators have blamed sabotage for the collapse of two separate bridges near the Ukrainian border
• In the Bryansk region, a road bridge collapsed, sending heavy trucks crashing down on to a moving enger train and killing at least seven people
• Pictures below show mangled carriages - officials say engers helped each other climb out of the wreckage in the dark
• Hours later in neighbouring Kursk, a railway bridge collapsed while a freight train was ing over it, injuring one of the drivers
• Ukraine's military intelligence says a Russian military train has been derailed outside Melitopol, southern Ukraine
• Without taking credit, the agency said an explosive device was set off as the train was ing, loaded with fuel and goods bound for occupied Crimea
• In the last few moments the commander of Ukraine's land forces has announced he is reg, citing a lethal strike on Ukrainian military training facility

Ukraine has conducted audacious attacks on Russia before - but this is a new levelpublished at 14:21 British Summer Time 1 June

14:21 BST 1 June

Paul Adams
Diplomatic correspondent, reporting from Kyiv

As Ukrainians digest today’s news, they are wondering if this is the most audacious attack on Russia yet.

Four airfields attacked across a vast area of Russia and, according to Ukrainian sources, more than 40 aircraft were hit, including some of Moscow’s huge strategic bombers.

Ukraine has attacked such aircraft before, but never on such a scale. Videos appear to show attack drones homing in on their targets as they sit on the tarmac.

It’s not clear how the attack was orchestrated, but given the small size of the drones involved, it’s likely that it was launched from inside Russia.

Earlier, Ukrainian and Russian officials gave differing s of two attacks on Russian trains, one of them carrying civilian engers.

Sources in Moscow spoke of Ukrainian terrorism, while a national security official here in Kyiv accused Russia of mounting a false flag operation to discredit Ukraine ahead of a round of peace talks due to take place in Turkey tomorrow.

All this came as Russia launched one of its biggest drone and missile attacks so far, on targets across Ukraine - 472 drones were recorded, the largest number in a single night.

Image source, Reuters

The photo above comes from footage posted on social media by the Irkutsk Governor Igor Kobzev. He says it shows a the aftermath of a drone attack on a military unit in the village of Sredniy, in the Irkutsk region.

Kobzev said that it was the first such attack in Siberia.

The latest wave of drone strikes on the Kremlin's military assets comes hours before Russia and Ukraine are set for the next round of peace talks in Istanbul.

Ukraine's President Volodymyr Zelensky said this morning that a delegation will be going to Turkey with the main aim of reaching a "complete and unconditional ceasefire".

Meanwhile, Russian media is reporting that a Russian delegation has departed for the talks in Turkey.

We're still getting information about Ukraine's massive drone attack on Russian bomber planes.

Here's a quick look at what we know so far:

• Ukraine's security service says it has launched a major operation to destroy Russian strategic bombers
• This campaign is targeting Russian planes on their home airbases - so far, Ukraine says it has hit 40 such locations, including in the Arctic
• Video released by the service appears to show explosions and smoke rising from the sites