At least 60,000 passengers have been stranded at airports across Russia because of a massive Ukrainian drone attack, local officials say.
Russia's Association of tour operators (Ator) says 350 flights have been affected since Tuesday evening in Moscow, St Petersburg, Sochi and several other cities.
The Russian defence ministry says 524 Ukrainian drones were destroyed in the past 24 hours – a record number if confirmed. No casualties were reported.
Ukraine says an overnight Russian drone and missile attack killed two people in Kyiv.
The barrage of strikes came as a self-declared Russian three-day ceasefire was set to begin on Wednesday night, ahead of a World War Two victory parade in Moscow on 9 May.
Kyiv has repeatedly rejected the truce idea as "theatrical play", reiterating its call for an unconditional 30-day ceasefire, which is also supported by Ukraine's allies in Europe and the US.
Russia has issued a set of tough pre-conditions for any possible settlement – a move described by Ukraine and many European politicians as an attempt to prolong the fighting and eventually force Kyiv to capitulate.
On Wednesday, US Vice-President JD Vance said "we think they [Russians] are asking for too much", in an apparent hardening of his stance towards Moscow.
"It's very important for the Russians and the Ukrainians to start talking to one another," Vance added.
He also took a far less strident tone towards Europe than he has in recent months, saying "I do still very much think the US and Europe are on the same team".
