A damaged house is seen after it was destroyed by debris of a Ukrainian drone on Thursday that was shot down by Russian air defense outside Belgorod, Russia. Three people, including a child, were killed in the Belgorod region overnight after drone debris fell on a private house, setting it on fire. Belgorod region governor Vyacheslav Gladkov Telegram channel via Associated Press

BUCHAREST, Romania — Romanian authorities said Thursday they found a crater from a suspected drone that may have exploded on impact on its territory near the border with Ukraine, reviving concerns about possible spillover of Russia’s war in Ukraine onto a NATO member country.

The predawn discovery of the crater nearly 2 miles west of the village of Plauru, which sits across the Danube River from the Ukrainian port of Izmail, was made after the Romanian Defense Ministry said it detected a series of drones heading toward Ukrainian river ports.

The ministry said the drone possibly exploded on impact, but it was not immediately clear when or from where the drone was launched. An investigation was underway.

“Heinous Russian attacks on Ukraine’s civilian infrastructure had again serious consequences on Romania’s territory,” Romanian Foreign Minister Luminita Odobescu wrote on X, the social media platform formerly known as Twitter, adding that “new evidence of impact was found on Romania’s soil.”

“We call on Russia to stop these war crimes,” she said.

Romanian authorities have confirmed drone fragments on the country’s territory in recent weeks and said the parts resembled those from drones used by the Russian army.

NATO Secretary-General Jens Stoltenberg told The Associated Press on Thursday that the alliance has increased the number of aircraft monitoring Romania’s skies after the drone findings. But he said there are no indications the drone incidents were “deliberate attacks on NATO’s allies, but more a consequence of the unjustified attacks on Ukraine.”

Asked if any member countries had talked of activating official consultations under Article 4 of the NATO treaty, which is the process for when members are worried about their security or territorial integrity, Stoltenberg said that “so far there hasn’t been any need for that.”

Romanian President Klaus Iohannis called the drone fragment discoveries “an absolutely unacceptable violation of the sovereign airspace of Romania, a NATO ally, with real risks to the security of Romanian citizens in the area.”

The recurring incidents over the past month have left some residents living near the border nervous that the war could spill into their country. The village of Plauru erected prefabricated concrete shelters for residents last month.

Separately Thursday, the governor of Russia’s Belgorod region on the border with Ukraine said three people, including a child, were killed and two others injured overnight when drone debris fell on a private house, setting it on fire.

The drone was shot down by Russian air defense systems, but the debris “effectively destroyed” two private houses on the outskirts of the city of Belgorod, the region’s capital, and damaged several more, Belgorod Gov. Vyacheslav Gladkov said.

The Belgorod region has been a regular target of cross-border shelling and drone attacks. Ukrainian officials have never acknowledged responsibility for attacks on Russian territory.

In Ukraine, the office of President Volodymyr Zelensky said at least 10 civilians were killed and 18 people injured over the past 24 hours, including from a missile strike on the southern city of Nikopol that hit a school, killing four and injuring two. A total of 50 homes, infrastructure facilities, and power lines were damaged in the city on the Dnipro River, Zelensky’s office said.

Ukraine’s air force said it intercepted 28 of 33 Shaheed drones that Russia launched overnight across the country. Gov. Oleh Kiper of the southern Odesa region – in which Izmail is located – said Russian forces had targeted Danube port infrastructure in the region, wounding one person.

In recent weeks, Russia has carried out sustained attacks on Ukraine’s Danube ports as part of its attempt to disrupt Ukraine’s ability to export grain to world markets.

In the eastern Donetsk region, intense and incessant fighting continued near the city of Avdiivka, said Vitalii Barabash, the head of the city’s military administration.

“A very tense situation for the third day. The battles around the city do not cease, and the shelling, both at positions and within the city itself, does not stop,” Barabash said on Ukrainian television.

Zelensky posted on Telegram that “we are holding our ground” in the city. A day earlier, the Ukrainian leader joined a meeting of more than 50 defense leaders from around the world and made a personal pitch for more military aid for his country in the face of the Russian onslaught.

White House National Security Council spokesman John Kirby on Thursday pushed back against the notion that U.S. bandwidth will be exhausted by the Israel-Gaza conflict and could provide an opening for adversaries, including in Moscow.

“We’re a big enough, strong enough nation, and we’ve got global responsibilities to look after our national security interests anywhere and everywhere,” Kirby said.

The Czech Republic and Denmark on Thursday pledged to send Ukraine more Western weapons. The Czech Foreign Ministry said the package, to be sent in the coming months, will include 50 infantry fighting vehicles and battle tanks, 500 heavy machine guns, 280 self-propelled howitzers, 7,000 anti-tank weapons, 60 mortar systems, and anti-drone systems.

Ukraine’s Interior Ministry said the death toll from last week’s missile attack that leveled a cafe in the village of Hroza, in the northern Kharkiv region, had risen to 59, following the identification of more victims.

The Hroza attack is one of the deadliest strikes by Russian troops in Ukraine since the invasion in February last year. Numerous bodies were found torn to pieces, and it took nearly a week to identify those who were killed when the Russian Iskander missile slammed into the cafe.

Associated Press journalists Hanna Arhirova in Kyiv, Ukraine; Lorne Cook in Brussels; Karel Janicek in Prague; and Yuras Karmanau in Tallinn, Estonia, contributed to this report.