Russian forces targeted Ukraine’s energy and gas infrastructure in a “massive” night time missile attack and Ukrainian drones struck an important oil refinery inside Russia, officials said, as the almost three-year war rumbled on against a backdrop of renewed diplomatic efforts to end it.

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.