Russian forces have launched a large-scale drone assault across Ukraine, where officials said three people were killed and 64 others wounded.

A concentrated, nine-minute-long Russian drone attack on Ukraine's second largest city of Kharkiv in the middle of the night killed six people and injured 64, including nine children, Ukrainian officials said on Wednesday.

The assault continued Moscow’s stepped-up drone and missile attacks, which have been ratcheting up for months with nightly bombardments on regions and cities in Ukraine.