WARSAW, Poland (AP) — The Polish military said early Wednesday that it had downed drones that violated its airspace as Russia launched a wave of aerial attacks on Ukraine.

Prime Minister Donald Tusk wrote on X that he had received a report from the Operational Command of the Army about “the shutting down of drones that entered our airspace and could constitute a threat.”

He said he informed the NATO Secretary General about actions undertaken by the Polish side.

Poland’s armed forces were on a heightened state of alert overnight Tuesday and early Wednesday because of what they described as “further massive airstrikes against targets located in Ukraine.”

Warsaw’s Chopin Airport warned passengers on its website that flight operations were on hold due to closure of the airspace over part of the country, but that the airport remained open.