Poland closed four airports, including its main Chopin Airport in Warsaw Wednesday, according to the U.S. Federal Aviation Administration, after Russia launched drone strikes near the border in neighboring Ukraine.

Poland’s armed forces said in a post on X that military aircraft had been activated to ensure airspace safety, although there was no official confirmation from the command that any airports had been closed.

“Polish and allied aircraft are operating in our airspace, while ground-based air defense and radar reconnaissance systems have been brought to the highest state of readiness,” the military’s operational command said in a post on X.

The U.S. Federal Aviation Administration said the Rzeszow–Jasionka Airport in Poland’s southeast, a hub for passenger and arms transfers to Ukraine, was among the airports that had been temporarily closed.

Earlier, Ukraine’s air force reported that Russian drones had entered NATO-member Poland’s airspace, posing a threat to the city of Zamosc, but it subsequently removed that statement from the Telegram messaging app.