A Russian missile strike targeted a Ukrainian training exercise near the Sumy border, killing six personnel and wounded more than ten, BBC reported.

Russia's military ministry released footage of the attack, and Tass reported up to 70 casualties, which have yet to be verified.

Sumy, which has been regularly shelled, serves as a launch point for Ukraine's advance into Russia's Kursk area, with the goal of creating a protective buffer zone despite significant Ukrainian losses, according to BBC.

The Russian footage shows soldiers walking in front of a missile explosion, surrounded by dense smoke.