Russian drones hit a Ukrainian port town on the Danube River, local authorities said on Monday, destroying a grain hangar in an apparent escalation of efforts to cripple Ukraine’s ability to export agricultural products, one of the country’s leading industries.
The explosions in the town of Reni — just across the river from Romania, a NATO member — would be the closest Russia has come to hitting alliance territory and risking a more direct confrontation with the United States and its European allies.
Ukrainian officials and Romania’s president blamed the attack on Russia, which has spent the past week bombarding Ukrainian ports near the city of Odesa after pulling out of a deal that enabled Ukraine to ship its grain across the Black Sea.
The origin of the drones could not be independently verified, and Russia’s defense ministry made no reference to an attack in the Odesa region in its daily update about the war.
But the strike on a river port about 70 miles from the coast appeared to signal that Moscow had expanded its campaign against Ukraine’s agricultural exports by targeting alternate routes for grain to reach world markets.
Global wheat prices, which rose last week after Russia pulled out of the Black Sea deal, rose by around 6.2 percent in Monday afternoon trading.
A local news website in Reni, a town of around 18,000 people, published a photograph of the aftermath. The town is more than 130 miles southwest of the city of Odesa, the focus of recent attacks on shipping infrastructure, and lies on the east bank of the Danube, just a few hundred yards from Romania.
Russia has previously fired on western Ukraine near the border with Poland, also a NATO member, but had not hit Ukrainian facilities so close to territory covered by the military alliance’s commitment to respond jointly to an attack on a member state.
President Klaus Iohannis of Romania said on Twitter that he condemned an attack by Russia on Ukrainian infrastructure close to his country’s borders and said the “recent escalation poses serious risks to the security in the Black Sea,” as well as affecting Ukrainian grain shipments and global food security. He did not specifically mention the drone strike in Reni.
Romania’s ministry of defense said it was maintaining a posture of “enhanced vigilance” with its allies along the alliance’s eastern flank.
“There are no potential direct military threats against our national territory or Romania’s territorial waters,” the ministry said in a statement.
The attack came after a week of increased hostilities in the Black Sea region, with Russia sending a nightly barrage of missiles into the city of Odesa, while first Russia and then Ukraine warned that they might target ships heading to their adversary’s ports.
Pro-war Russians praised the Danube strikes as a further step toward destroying Ukraine’s economy and blocking Western arms deliveries. They said that Ukraine had been taking advantage of the Reni port’s proximity to NATO territory — and the fact that ships can approach it along the Danube without having to sail through Ukrainian territorial waters in the Black Sea — as a way of continuing to export grain and other goods.
“It looks like they’re blocking this way of evading the sea blockade of Kyiv,” a Russian talk show host, Olga Skabeyeva, declared on the Rossiya state television channel on Monday. “And soon they’ll completely deny Ukraine access to the Black Sea.”
A popular pro-war blog, Rybar, claimed the port was being used to supply Ukraine’s military while also serving as a channel for exporting grain. A Russian state television war reporter, Yevgeny Poddubny, wrote on Telegram that the strikes were part of the “critically important” mission of “breaking every thread of Ukraine’s maritime traffic.”
The chances the grain initiative could be revived have grown increasingly slim over the past week. On Monday, Russia’s F.S.B., the successor to the Soviet-era K.G.B., claimed that it had evidence that, in May, Ukraine had imported explosives across the Black Sea to one of its Danube River ports. The claim could not be independently verified.
The drone attack occurred over the course of four hours, Oleh Kiper, the head of the regional military administration, wrote on the Telegram messaging app, adding that three drones were shot down by Ukraine’s air defenses. Seven people were injured, he said.
The Danube River delta, a network of waterways crisscrossing the border region between Ukraine, Romania and Moldova, was rarely used to export Ukrainian grain before Russia started its full-scale invasion in February 2022, but has over the past year become an indispensable freight lifeline.
Ukraine has been exporting around two million metric tons of grain per month through its Danube River ports, according to Benoît Fayaud, deputy executive director of Stratégie Grains, an agricultural economy research firm.
The attack on Reni could deter commercial vessels from using the port in the short term and could raise the cost of insurance, Mr. Fayaud said.
Yurii Shyvala and Anton Troianovski contributed reporting.