Poland’s military said early Wednesday that it had shot down drones that violated its airspace during a Russian attack on neighboring Ukraine, in what is potentially a major provocation for Europe.

“This is an act of aggression that posed a real threat to the safety of our citizens,” said Poland’s Operation Command in a post on X Tuesday morning.

Prime Minister Donald Tusk confirmed a military response operation was underway “related to multiple violations of Polish airspace” and said “the military has used weapons against the objects.”

Poland is a member of the NATO alliance, a transatlantic defense pact involving the US that employs the principle that an attack on one is an attack on all.

Defense Minister Wladyslaw Kosiniak-Kamysz said Poland was “in constant contact with NATO command.”

“Territorial Defense Forces have been activated for ground searches of downed drones,” he said.

He urged people to “remain calm” and said anyone who found fragments of military equipment should report it to authorities.

The Operation Command said the military operation was ongoing and its units were “fully prepared for immediate response.” It urged residents to stay in their homes, saying the areas of Podlaskie, Mazowieckie, and Lubelskie Voivodeships were the most “at risk.”

US Secretary of State Marco Rubio told CNN that he has been briefed on reports of Russian drones over Poland.

“Yes,” he said when asked by CNN if he had received a briefing, as he left a dinner with President Donald Trump on Tuesday night.

Earlier, Polish authorities closed Warsaw International Airport and the military said Polish and NATO aircraft have been scrambled as reports have surfaced of Russian drones over the country.

The Polish military’s Operational Command said in a statement that “ground-based air defense and radar reconnaissance systems have reached the highest level of alert” after Russia launched massive airstrikes on Ukrainian territory.

“To ensure the security of Polish airspace, the Operational Commander of the Polish Armed Forces has activated all necessary procedures,” the statement said, adding that the Polish military is “fully prepared for immediate response.”

A Notice to Airmen (NOTAM) posted on the US Federal Aviation Administration’s website said Warsaw Chopin Airport and at least two other airports in Poland were unavailable “due to unplanned military activity related to ensuring state security.”

Before the NOTAM was posted, the Ukrainian Air Force said on the Telegram messaging app that drones were heading west and threatening the city of Zamosc in Poland, but the statement has since been deleted, Reuters reported.

It was not immediately clear how many drones entered Poland’s airspace.

Ukrainian media reported that at least one drone was heading towards the western Polish city of Rzeszow.

CNN cannot independently verify the reports.

Rzeszów–Jasionka Airport, in the southeast of Poland, has also been closed, according to a NOTAM. The airport has been a logistics hub for NATO aid to Ukraine, though the United States pulled its forces from the base earlier this year.

The airport in Lublin, Poland, southeast of Warsaw, was also unavailable due to military activity, another NOTAM said.

The military activity over Poland comes less than a week after Russian President Vladimir Putin was in China, where he met with leader Xi Jinping and North Korean leader Kim Jong Un in show of unity between the authoritarian allies.

Since that meeting, Russia has staged its largest aerial assaults on Ukraine since it invaded its neighbor more than three years ago.

The attacks in recent days have largely targeted residential areas around the country and in the capital of Kyiv. On Tuesday, 24 civilians were killed in a Russian strike on the village of Yarova in the eastern Donetsk region, Ukrainian officials said.

Last weekend, Russia deployed more than 800 drones in its largest attack to date, striking a government building in Kyiv for the first time.

The attack hit the Cabinet of Ministers building, which houses the prime minister’s office, as well as some government ministries.

All these attacks have come less than a month after a Putin summit with US President Trump in Alaska that ended without a deal to end the war. Any progress made has long since evaporated with Russia’s expanded aerial attacks.

Poland earlier announced it was closing its eastern border with Russian ally Belarus, due to joint Russian-Belarusian military exercises beginning Friday, Reuters reported.

The Zapad 25 large-scale exercises, which will take place in western Russia and Belarus, have raised security concerns not only in Poland but also in the neighboring NATO countries on Lithuania and Latvia, according to Reuters.

“On Friday, Russian-Belarusian maneuvers, very aggressive from a military doctrine perspective, begin in Belarus, very close to the Polish border,” Polish Prime Minister Donald Tusk told a government meeting, Reuters reported.

“Therefore, for national security reasons, we will close the border with Belarus, including railway crossings, in connection with the Zapad maneuvers on Thursday at midnight,” Tusk said.

This is a breaking story and will be updated.

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