WOHYN, Poland (AP) — Multiple Russian drones crossed into Poland in what European officials described Wednesday as a deliberate provocation, causing NATO to send fighter jets to shoot them down. A NATO spokesman said it was the first time the alliance confronted a potential threat in its airspace.

The incursion, which occurred during a wave of strikes by the Kremlin on Ukraine, and the NATO response swiftly raised fears that the war could spill over — a fear that has been growing in Europe as Russia steps up its attacks and peace efforts go nowhere.

Poland requested an emergency meeting of the U.N. Security Council on the drone incursion. South Korea’s U.N. Mission, which holds the council presidency this month, said the time was being discussed.

Russia’s Defense Ministry said it did not target Poland, while Belarus, a close ally of Moscow, said it tracked some drones that “lost their course” because they were jammed.

However, several European leaders said they believed the incursion amounted to an intentional expansion of Russia’s assault against Ukraine.

“Russia’s war is escalating, not ending,” European Union foreign policy chief Kaja Kallas told reporters in Brussels. “What (Russian President Vladimir) Putin wants to do is to test us. What happened in Poland is a game changer,” and it should result in stronger sanctions.

Polish airspace has been violated many times since Russia’s full-scale invasion of Ukraine in 2022, but never on this scale in Poland or anywhere else in NATO territory.

Poland said some of the drones came from Belarus, where Russian and Belarusian troops have begun gathering for war games scheduled to start Friday.

It was not immediately clear how many drones were involved. Polish Prime Minister Donald Tusk told parliament 19 violations were recorded over seven hours, but he said information was still being gathered. Polish authorities said nine crash sites were found, with some of them hundreds of kilometers from the border.