Overnight Russian drone attacks sparked a fire in Kyiv and injured a woman and damaged several houses in the northeastern city of Sumy, Ukrainian officials said on Monday. The Ukrainian military said on Monday that it had shot down 61 out of 83 drones with 22 more likely downed by electronic warfare.

Ukraine has, for some time, fielded large "mothership" drones that can carry and eventually deploy a set of smaller attack drones. This approach can, for example, get light and fast FPV attack drones behind the front lines before releasing them, thereby extending the attack drones' limited range.

Ukraine has launched its second major drone attack in a week against Russian oil refineries hundreds of miles from its borders.

Russia launched ballistic missiles and more than 100 drones in a wave of attacks across Ukraine overnight that killed three people and injured at least 16, including a child, authorities said.

A Ukrainian drone attack overnight sparked a fire at an oil depot in Russia's southern region of Krasnodar that has since been extinguished, regional officials said on Wednesday.

One person was killed and four were injured by a Russian overnight strike on a Kyiv office block, part of a wave of drone and missile attacks that hit 11 regions across Ukraine.