Russian drones struck energy sites early on Wednesday and knocked out power to some parts of Ukraine's northern Sumy region, officials said.

The Sumy regional authority, in a post on the Telegram messaging app, said the drones hit the cities of Shostka and Konotop, northeast of Kyiv and near the Russian border. Ukraine's air force shot down seven drones used in the attack, according to the regional authorities.

The Ukrainian military said it had shot down all 24 drones Russia launched in the overnight attack, which targeted five other regions in the country's south and east.

Emergency services were working to restore power, with electricity back in three districts as of Wednesday morning.

As Russian troops pushed their way across the border into northeastern Kharkiv region a little more than a week ago, officials have warned about a buildup of troops and a possible push into the adjacent Sumy region.

(Reporting by Ron Popeski and Anastasiia Malenko; Editing by Stephen Coates and Gerry Doyle)