Ukraine has intensified its drone attacks on Russia, setting fire to a major oil refinery in the south and killing at least two people, according to Russian authorities.

A "massive" Ukrainian drone strike killed one person and wounded another in southern Russia and caused a fire in a refinery, the regional governor said on Sunday.

Ukraine has intensified its drone attacks on Russia, setting fire to a major oil refinery in the south and killing at least two people, according to Russian authorities.