WARSAW — Poland’s military said early Wednesday that it had shot down drones that violated its airspace during a Russian attack on neighboring Ukraine, the first time it has taken such a step in what is a major provocation for Europe and NATO forces.

“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 Wednesday morning.

Prime Minister Donald Tusk said it was the first time Russian drones had been shot down over the territory of a NATO member state and the incursion involved a “huge number” of them.

“We are most likely dealing with a large-scale provocation,” Tusk said on Polish Television, following an emergency meeting of Poland’s National Security Bureau.

He said the “situation is serious” and that the country was “ready to repel” this type of attack.

“The security of our homeland is our highest priority,” Polish President Karol Nawrocki said.

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. European faith in the reliability of that pact has been shaken under US President Donald Trump who, alongside key cabinet members, have called on Europe to the lead in its own defense.

Tusk said he was in constant communication with the secretary general of NATO and Poland’s allies.

The European Union’s foreign policy chief, Kaja Kallas, called it “the most serious European airspace violation by Russia since the war began.” She said “indications suggest it was intentional, not accidental,” adding: “Russia’s war is escalating, not ending.”

The Polish military thanked NATO member the Netherlands for contributing F-35 fighter jets to defensive operations overnight, which have now concluded.

Ukraine’s President Volodymyr Zelensky said at least eight “Shahed” drones had been aimed toward Poland, in what he called “an extremely dangerous precedent for Europe.” His own country endured a Russian attack involving 415 drones and 40 missiles overnight.

The leader of the newest NATO member, Sweden, called the presence of Russian drones over Poland “unacceptable.”

“The Russian war of aggression against Ukraine poses a threat to the security of all of Europe,” Swedish Prime Minister Ulf Kristersson said in a post on X.

“Russia is deliberately expanding its aggression, posing an ever-growing threat to Europe,” said Gitanas Nauseda, the president of Lithuania, also a NATO member.

The drone incursion comes as Trump’s attempts to strike a peace deal between Russia and Ukraine have ground to a halt, with Moscow only scaling up its aerial assaults.

Ukrainian Foreign Minister Andrii Sybiha said Russian President Vladimir Putin is “testing the West.”

“Russian drones flying into Poland during the massive attack on Ukraine show that Putin’s sense of impunity keeps growing,” Sybiha said in a post on X.

Ned Price, a US State Department spokesperson during the Biden administration, also thought Russia may have sent drones over Poland to test NATO resolve and defenses.

While cautioning it could be the case that the drones flew over Poland by mistake or because of Ukrainian countermeasures, Price told CNN’s Laura Coates their presence, if deliberate, could expose what Russia might see as “weakness.”

US Sen. Dick Durbin, an Illinois Democrat, was more direct.

“Repeated violations of NATO airspace by Russian drones are fair warning that Vladimir Putin is testing our resolve to protect Poland and the Baltic nations,” Durbin said in a post on X.

Polish Defense Minister Wladyslaw Kosiniak-Kamysz said Territorial Defense forces had been activated to search for downed drones.

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

Earlier, authorities closed airspace over Warsaw International Airport and other smaller airports “due to unplanned military activity related to ensuring state security,” according to a Notice to Airmen (NOTAM) posted on the US Federal Aviation Administration’s website.

The Warsaw airport reopened Wednesday morning, Mayor Rafal Trzaskowski said in a post on X.

Earlier, 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.

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. — CNN