Explosions were heard in Sumy. Earlier, the Air Force of the Ukrainian Armed Forces warned of the threat of air strikes on the frontline regions, UNN reports .
Sounds of explosions were heard in Sumy, Suspilne correspondents report.
Earlier, the Air Force warned of enemy tactical aircraft activity in the northeast.
"There is a threat of using air strikes in the frontline areas," the Ukrainian Armed Forces said in a Telegram post.