The overnight attack damaged multi-storey residence blocks and destroyed scores of cars in the city centre, Oleh Synehubov, the governor of the region bordering Russia, said on the Telegram messaging app.

A photograph provided by regional authorities showed the damaged facade of a multi-storey brick building with windows blown out, as flames burned on an upper floor and debris and broken tree branches littered the area.

The teenagers were among the injured, Vitali Karabanov, head of Balakliia’s military administration, said on Telegram, while nine of the injured were admitted to the hospital.

Moscow made no immediate comment on the attack.

Russia has rained down regular missile, drone and artillery strikes on Ukraine’s second-largest city of Kharkiv, smashing homes and infrastructure, severing power links and subjecting residents to constant air-raid alerts.

Both sides deny targeting civilians in the war that Russia launched nearly four years ago, but thousands have been killed in the conflict, the vast majority of them Ukrainian.

Russian air defence forces destroyed 36 Ukrainian drones over seven Russian regions overnight on Monday, the defence ministry said.

Parts of the region, and the city of Izyum in its south, had no power supply overnight, after Russia’s attacks late on Sunday injured a 14-year-old, city authorities said on Telegram.

Denis Pushilin, the top Russian-backed official in Donetsk, said an attack by Ukrainian strike drones on energy infrastructure had left roughly 500,000 people without power across several districts.

Work was continuing to restore the electricity supply, Pushilin wrote on Telegram.

The governor of the Ulyanovsk region, east of Moscow, said an attack by a Ukrainian drone on a substation there had been repelled.

There were no casualties and the power supply was unaffected, Alexei Russkikh wrote on Telegram.