Ukrainian President Volodymyr Zelensky has condemned as "terrorism" a Russian drone attack on a passenger train that local officials say killed at least four people, BBC reported. 

Zelensky said another four people were missing after the train with more than 200 people on board was hit in Ukraine's north-eastern Kharkiv region on Tuesday.

Earlier, officials in Ukraine's southern port of Odesa said three people were killed in an overnight Russian drone attack, according to BBC.