"As a result of the air strike, two people died, (and) four more people were injured, including two children," military authorities said in a statement.

"Necessary medical assistance is provided to the wounded."

The city's mayor, Oleksiy Drozdenko, said homes and vehicles were also destroyed.

"All services are on site," he said in a Telegram post.

Sumy lies just across the border from Russia's Kursk region, where Kyiv launched a shock offensive on August 6, aimed in part at creating a "buffer zone" inside Russia.

Sunday's strike came just over a week after another fatal attack in the city that killed two people and wounded eight others.

Regional authorities said at the time that people in 183 Sumy settlements near the Russian border were being urged to evacuate, and that tens of thousands of others in the area had already done so.