Russia for the first time on Monday attacked a port on the Danube River in Ukraine, close to the Romanian border, Ukrainian and Romanian officials said, destroying a grain hangar in an escalation of its efforts to cripple Kyiv’s agriculture and risking a more direct confrontation with the United States and its European allies.
The assault on the port in the town of Reni, across the river from Romania, a NATO member, targeted Kyiv’s alternative export routes for grain to reach world markets, days after Russia terminated a deal that had enabled Ukraine to ship its grain across the Black Sea. The attack is the closest Moscow has come to hitting the military alliance’s territory since Russia’s full-scale invasion of Ukraine last year.
The port strike came amid two drone attacks in central Moscow on Monday morning that Russian officials blamed on Ukrainian forces. At least two nonresidential buildings were hit about 4 a.m. local time, Mayor Sergei Sobyanin of Moscow said on the Telegram messaging app. He added that there had been no “serious damage or casualties.”
Ukrainian and Romanian officials denounced the port strike, with President Klaus Iohannis of Romania condemning the attack on Ukrainian infrastructure close to his country’s borders. He said on Twitter that the “recent escalation poses serious risks to the security in the Black Sea,” as well as affecting Ukrainian grain shipments and global food security.
Romania’s Defense Ministry said it was maintaining a posture of “enhanced vigilance” with its allies along the alliance’s eastern flank. But the ministry added in a statement that “there are no potential direct military threats against our national territory or Romania’s territorial waters.”
Since the Kremlin pulled out of the Black Sea Grain Initiative last week, its forces have launched a barrage of attacks nearly every night on the city of Odesa — which is about 130 miles from Reni — and its Black Sea port, destroying grain stocks and infrastructure. Those attacks, along with Moscow’s warning that it would consider any ship approaching Ukraine’s Black Sea ports as potentially carrying military cargo, made Ukraine’s alternative grain routes more vital.
Ukraine, a major producer of grain and other food crops, has been exporting around two million metric tons of grain per month through its Danube ports, according to Benoît Fayaud, the deputy executive director of Stratégie Grains, an agricultural economy research firm.
The attack in Reni, about 70 miles from the coast, could deter commercial vessels from using the port in the short term and raise the cost of insurance, Mr. Fayaud said.
Global wheat prices rose by around 5.5 percent in Monday morning trading.
The Moscow and Danube attacks occurred amid a grinding war that has seen Ukraine mount a slow counteroffensive to take back territory seized by Russian forces. Kyiv has rarely admitted to attacking Russian territory far from the front line, but the drone strike in Moscow was not the first since the war began.
In May, eight drones targeted Moscow, the Russian capital, shattering windows in three residential buildings and injuring two residents, according to officials. The strikes confronted Muscovites with the reality of Russia’s war in Ukraine, which President Vladimir V. Putin had worked to shield from their daily lives. That assault came after Russian forces had launched another in a series of overnight attacks on Kyiv, the Ukrainian capital.
After the drone strikes on Monday, videos verified by The New York Times showed damage in at least two locations near the Moskva River in southern Moscow. One building struck is about a block from the Russian National Defense Management Center, an imposing structure used to conduct “centralized combat management of the Russian armed forces,” according to the ministry’s website.
Smoke could be seen rising from the top floors of a high-rise building housing a French home-improvement chain. Other footage showed damage to several structures along Komsomolsky Prospect — an avenue that runs through one of the most upscale parts of central Moscow and that is close to the Defense Ministry — including the building housing the Military University and the Central Military Band, a performance group of the Russian Armed Forces.
It was not possible to determine whether drones had caused the damage. But the authorities blocked off part of Komsomolsky Prospect after finding one of the drones there, state news media reported. The Russian authorities said they had destroyed two drones.
Later on Monday, another drone crashed near a residential building in Pervomaiskoe, Russia, but no injuries were immediately reported, according to local news outlets.
The Danube port attack occurred over the course of four hours, Oleh Kiper, the head of the regional military administration in that area of Ukraine, wrote on Telegram. Ukraine’s air defenses shot down three drones, he said, adding that seven people were wounded, three from shrapnel. One had serious injuries.
Mike Lee, director of Green Square Agro Consultancy, which specializes in the Black Sea and Eastern Europe, called the attack on Reni a “massive escalation” by Moscow in terms of the effect it could have on Ukraine’s ability to use alternative routes for its exports.
Russia fired last year 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. NATO and Poland said that what had detonated a few miles outside Ukraine’s border in November most likely had been a remnant of a Ukrainian surface-to-air missile, though U.S. and NATO officials still held Russia responsible as the aggressor.
Cheerleaders of Russia’s war praised the strikes on the port as a further step toward destroying Ukraine’s economy and blocking what they described as Western arms deliveries.
They said that Kyiv had been taking advantage of the port’s proximity to NATO territory — and the fact that ships can approach it along the Danube without sailing through Ukrainian waters in the Black Sea — as a way of continuing to export grain and other goods during the war.
“It looks like they’re blocking this way of evading the sea blockade of Kyiv,” a Russian talk show host, Olga Skabeyeva, said on the Rossiya state television channel. “And soon they’ll completely deny Ukraine access to the Black Sea.”
A popular pro-war blog, known as Rybar, also claimed that the Reni port was being used to supply Ukraine’s military, along with exporting grain.
On Monday, the F.S.B., Russia’s successor to the K.G.B., claimed that it had evidence that Ukraine imported explosives in May across the Black Sea to one of its Danube ports. The claim could not be independently verified.
The Danube River delta, a network of waterways crisscrossing the border region of Moldova, Romania and Ukraine, had been rarely used to export Ukrainian grain before the invasion, but over the past year, it has become indispensable.
The grain deal first brokered by the United Nations and Turkey last year covered a trio of major Black Sea ports, and enabled Ukraine to ship more than 30 million tons of grain. At the same time, smaller ports on the Danube that were not part of the deal were able to send out shipments that wended their way to the Black Sea and on to international destinations.
Those routes — as well as overland pathways — became vital after Russia terminated the Black Sea deal, saying its demands had to be met. Moscow had complained bitterly that the deal was biased toward Kyiv and that Western sanctions that restricted the sale of its own agricultural products should be lifted, among other demands.
The United Nations has said that Russia’s attempts to stop Ukraine’s exports would exacerbate a hunger crisis faced by some countries in Africa and the Middle East. Ukraine exports grain via road and rail into European Union countries, as well as via the Danube ports.
Since the start of the war, Ukraine has sent more than 20 million tons of grain to foreign markets through Romania and millions more by train through Poland, a inflow that infuriated East European farmers who said it drove down local prices. After protests in some E.U. countries, the bloc allowed Bulgaria, Hungary, Poland, Romania and Slovakia to ban domestic sales of Ukrainian wheat, corn, rapeseed and sunflower seeds, though it continued to allow the transit of those items for export elsewhere.
The ban is expected to end on Sept. 15. Last week, ministers from those five countries called for the bans to be extended.
On Monday, President Volodymyr Zelensky of Ukraine pushed back on that idea, saying on Telegram that extending the ban would be “unacceptable in any form.”
Yurii Shyvala, Anton Troianovski and Gabriela Sá Pessoa contributed reporting.