Afghanistan, Sept. 10 -- Poland's military shot down Russian drones that violated its airspace during Ukraine strikes, raising NATO security concerns as Warsaw placed defenses on highest alert.

Poland's military said on Wednesday it had shot down Russian drones that crossed into its airspace during overnight strikes on Ukraine, describing the incident as an act of aggression. The Operational Command confirmed the interceptions took place in the early hours of September 10.

According to international media reports, the Polish army stated that its air defense and radar systems had been placed on the highest state of alert. The number of drones that entered Polish airspace has not been disclosed.

Prime Minister Donald Tusk said the incursio...