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.

Officials say Russian forces have targeted Ukraine’s energy and gas infrastructure in a “massive” nighttime missile attack, while Ukrainian drones struck an important oil refinery inside Russia.

Russian forces have escalated their drone attacks on Ukrainian cities, notably Kyiv and Sumy, resulting in significant damage and civilian casualties. In Kyiv, a drone strike ignited a fire in a non-residential building;