Poland says it has shot down several Russian drones that crossed its airspace during overnight strikes on Ukraine, accusing Moscow of staging its most serious provocation since the war began in 2022.

According to Polish authorities, 19 drones entered from Belarusian airspace late Tuesday, forcing NATO allies to scramble fighter jets in response. Prime Minister Donald Tusk called the incident “a large-scale provocation,” telling parliament:

“We are not on the brink of war — but a line has been crossed. This is the closest Poland has come to open conflict since World War Two.”

Four drones were intercepted and destroyed, officials confirmed, after the military urged residents in three eastern regions to shelter indoors. Air traffic at Warsaw and Rzeszów airports was suspended for several hours before operations resumed on Wednesday morning.

Warsaw invoked Article 4 of NATO’s founding treaty — only the eighth time in history the clause has been triggered — calling for urgent consultations with allies. NATO’s European Command said fighter jets were “scrambled quickly and decisively,” with the Dutch air force deploying F-35s to assist.

Russia denied responsibility, dismissing Poland’s accusations as “groundless.” Moscow’s ambassador to Warsaw, Andrei Ordash, claimed there was “no evidence” linking the drones to Russia and insisted the Kremlin had “no interest in escalating tensions with Poland.” Belarusian officials echoed this, arguing the drones “strayed off course” and claiming they had also shot some down.

European leaders were quick to condemn the breach. EU foreign policy chief Kaja Kallas called it “the most serious violation of European airspace by Russia since the start of the invasion,” warning it appeared “intentional, not accidental.” Ukrainian President Volodymyr Zelenskyy echoed that assessment, saying intelligence pointed to a deliberate strike.

Baltic and Nordic allies rallied behind Poland, with Lithuania’s President Gitanas Nausėda accusing Moscow of “deliberately expanding its aggression,” while Estonia’s foreign minister Margus Tsahkna said the event underscored that “Russia is a direct threat to Europe and NATO, not just Ukraine.”

Security analysts warned the drone incursion may have been a calculated test of NATO’s resolve.

“Putin is probing NATO’s red lines,” said Michael Bociurkiw, senior fellow at the Atlantic Council. “Poland is now more exposed and more central to this conflict than ever before.”

Poland, a critical logistics hub for Western arms shipments to Ukraine, has been on high alert since the start of the war. Previous missile incidents — including the 2022 strike that killed two Poles — had already raised tensions. But Wednesday’s drone breach marks the most direct confrontation between Moscow and a NATO member to date, pushing the alliance into uncharted territory.