BUCHAREST, Romania (AP) — A Russian drone that was part of an attack on Ukraine went astray and struck an apartment building in eastern Romania, injuring two people in the NATO member country, Romanian officials said Friday. The incursion added to concerns that the war could spread across the alliance’s borders.

The drone was tracked overnight by radar in Romanian airspace, crashed onto the roof of the building in the Danube port city of Galati and sparked a fire, the Defense Ministry said in a statement. The two injuries were minor and several people were evacuated.

It was the latest in a series of drones — from both Russia and Ukraine — to hit a NATO member since Moscow launched its full-scale invasion in February 2022.

The incidents have left the 32-member military alliance on edge. Friday’s incursion drew strong condemnation across Europe, with leaders calling Russia’s actions reckless and irresponsible.

Romania scrambled two F-16 fighter jets and a helicopter, and alerted residents of the affected areas, but the aircraft didn’t engage the drone in the city, which is located near the borders of Ukraine and Moldova.

Romania asked NATO to speed up the transfer of anti-drone capabilities to its military, the Foreign Ministry said, calling the incursion a serious violation of international law.

Asked about the drone during a state visit to Astana, Kazakhstan, Russian President Vladimir Putin said its origin is yet to be determined, telling reporters that “no one can say what origin a particular aircraft has until it has been examined.” He urged Romania to turn the drone over to Russia for it to conduct “an objective investigation.”

But Romanian President Nicusor Dan identified the drone as Russian.

“We had a Russian drone, Geran-2, leaving Russia. We know the trajectory, we know where it went through Ukraine, we know where it entered Romania, part of a swarm of 43 Russian drones, of which only one reached Romanian territory,” a statement from Dan said.

He said later that investigators determined it was probably carrying at least 30 kilograms (66 pounds) of explosives.

Gen. Gheorghe Maxim, interim commander of the Romanian armed forces’ joint staff, told a news conference that the drone in Galati wasn’t “an attack from Russia against Romania,” but he added that “Romanians should understand that Russia is a threat to the security of the countries in the area.”

In Kyiv, Ukrainian President Volodymyr Zelenskyy said he had spoken to Dan, praising the country’s “principled, prompt, and strong” response. In a social media post, he said the countries’ militaries were in contact and that “we will remain in constant communication with Romania and continue working together to protect lives from all potential Russian threats.”