BUCHAREST, Romania — 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 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.”

Romania has confirmed drone fragments landed on its territory on multiple occasions since the war began, including in Galati last month, but no one was hurt in any of those incidents, with debris falling in remote areas.

Dan convened Romania’s top defense body Friday to discuss what he called “the worst incident to hit the national territory” since the war began.

After the Supreme Council of National Defense met in Bucharest, Dan said the Russian consul in the Black Sea port of Constanta has been declared persona non grata and that the consulate will be closed. Foreign Minister Oana Toiu summoned Russian Ambassador Vladimir Lipaev and told him the consul had 72 hours to leave Romania.

Territorial violations have become so common in Romania in recent years that lawmakers adopted legislation last year allowing the army to shoot down drones entering its airspace as a last resort. But the country has remained cautious in downing errant drones, which can pose risks to populated areas.

Russia has been using long-range missiles and drones to damage Ukraine’s power grid and hammer cities, and Ukraine has braced for further heavy bombardments. Kyiv also has sent long-range drones deep into Russia to attack oil refineries, military bases and and other infrastructure.

Friday’s incident adds to recent drone-related incursions in Europe. Ukrainian drones have hit the chimney of a power plant in Estonia and empty fuel tanks in Latvia, and also were shot down by Romanian fighter jets stationed in Lithuania. Ukrainian officials apologized and said the drones were aimed at military targets in Russia, but veered off course by Russian electronic interference.

Poland, Croatia, Romania and non-NATO member Moldova all have reported airspace violations and found drone fragments on their territory since the war began. The airspace violations have raised questions about the state of air defenses on NATO’s eastern flank.

A senior U.S. military official recently told reporters the number of “hybrid activities” — drone incursions, hacking attacks and other acts short of military force in Europe that can be attributed to Russia — have increased in recent years and are part of a campaign to achieve strategic objectives without actually going to war.

The official, who spoke on condition of anonymity to talk candidly about the ongoing situation, said it is believed that there's an opportunity for the U.S. and other NATO countries to be more aggressive in countering these actions, particularly since there is a belief that Russia won't see the responses as escalatory.

NATO Secretary-General Mark Rutte said he had spoken to Dan and expressed “absolute solidarity” with its ally.

"NATO stands ready to defend every inch of Allied territory. We will continue to enhance our readiness to deter and defend against any threat, including from drones,” he said in a post on X.

NATO allies spoke informally about the incursion, but no official meeting was scheduled Friday. Romania can request formal NATO consultations if it believes its territory or security is under threat.

European Commission President Ursula von der Leyen said Russia "has crossed yet another line,” while the European Union will keep strengthening security on its eastern frontier and will draft a 21st set of sanctions against Moscow.

Putin also was asked in Kazakhstan about comments from Lithuanian Foreign Minister Kęstutis Budrys, who said NATO is capable of destroying Russian military assets in Moscow's Baltic exclave of Kaliningrad. He responded that Russia “has every means to raze to the ground anyone who tries to do so.”

He said nations posing a direct military threat to Russia “are legitimate targets,” responding to an earlier claim by Russia’s Foreign Intelligence Service that Ukraine sent troops to Latvia to launch drones at Russia. Officials in Latvia and other Baltic nations rejected Moscow’s claims.

Estonian Foreign Minister Margus Tsahkna said the risk of such “serious incidents” was raised by “ Putin’s increasing nervousness, driven by military setbacks.”

French Foreign Minister Jean-Noël Barrot complained to the Russian ambassador about what he called “this latest irresponsible act,” saying they are "both reckless and pointless, as they will in no way deter us from our support for the Ukrainian resistance.”

Dmitry Medvedev, deputy chairman of Putin’s National Security Council, told European leaders to “just shut up” about the drone.

Medvedev, known for his provocative and inflammatory statements, said in an expletive-filed post on his messaging channel MAX that the leaders were “scoundrels” and “imbeciles” and that their countries were part of the “warring nations” in the conflict.

“European drones, their spare parts, and other weapons, not to mention intelligence data, are used daily in attacks on our country,” he wrote. “Their operations result in damage to residential buildings, killing civilians.”