ReutersUkraine's military has reported Russian drone attacks on several regions overnight, just hours after the end of a 30-hour "Easter truce" declared by Moscow.
Ukraine's air force issued raid alerts for the Kyiv region, as well as Kherson, Dnipropetrovsk, Cherkasy, Mykolaiv and Zaporizhzhia.
In the southern city of Mykolaiv, Mayor Oleksandr Senkevych said "explosions were heard". It was not immediately clear whether there were any casualties.
Russia's military has not commented on the reported attacks. The truce declared by President Vladimir Putin expired at midnight Sunday Moscow time (21:00 GMT). Both sides accused each other of violating the ceasefire.
In the early hours of Monday, residents in several Ukrainian cities, including the capital Kyiv, were urged by local authorities to go immediately to nearby shelters due to the threat of drone strikes.
The BBC has not independently verified the claims by Kyiv and Moscow.
US President Donald Trump - who has been pushing for an end to the war - said late on Sunday that "hopefully Russia and Ukraine will make a deal this week". He gave no further details.
Russia launched a full-scale invasion of Ukraine on 24 February 2022, and currently controls about 20% Ukraine's territory, including the southern Crimea peninsula annexed by Moscow in 2014.
It is estimated that hundreds of thousands of people - the vast majority of them soldiers - have been killed or injured on all sides since 2022.
Last month, Moscow came up with a long list of conditions in response to a full and unconditional ceasefire that had been agreed by the US and Ukraine.
