Ukraine has carried out a series of deadly strikes on targets in south-west Russia over the past 24 hours, according to Russian officials.
The Russian emergency ministry says 14 people including two children have been killed and dozens of others injured in the city of Belgorod.
A Ukrainian security source has confirmed to the BBC that Kyiv fired 70 drones at Russian military targets - and blamed Russian air defences for fragments falling in Belgorod.
The attack appears to be one of the deadliest strikes on Russia during the war so far.
Moscow has repeatedly accused Ukraine of drone strikes on its territory, though Ukraine has not claimed responsibility for these.
Saturday`s attacks follow Russian strikes on Ukraine on Friday which killed 39 people, according to Ukrainian President Volodymyr Zelensky.
Cities across Ukraine were attacked, including the capital Kyiv, Lviv in the west, Odesa and Zaporizhzhia in the south, and Dnipro and Kharkiv in the east.
Saturday`s strikes in Belgorod mark one of the deadliest days of attacks within Russia since it invaded Ukraine.
Such Ukrainian attacks on Russia are not rare, but they have typically killed fewer people.
For instance, in October, three people were killed when debris from a destroyed Ukrainian drone fell on Belgorod homes, while Ukrainian shelling killed two women in the Belgorod region in June.
