Russian drones on Wednesday hit a Ukrainian port city along the border with Romania, causing significant damage and a huge fire at facilities that are key to Ukrainian grain exports.

Ukrainian infrastructure minister Oleksandr Kubrakov said that about 40,000 metric tons (44,000 tons) of grain, which was expected by Africa, China and Israel, were damaged in the attack.

The attacks followed the end of a deal with Russia that had allowed Ukrainian shipments to world markets from the Black Sea port of Odesa.

Since scrapping the deal, Russia has hammered the country’s ports with strikes, compounding the blow to the key industry. In the past two weeks, dozens of drones and missile attacks have targeted the port of Odesa and the region’s river ports, which are being used as alternative routes.

The head of the Ukrainian president’s office, Andriy Yermak, said the city of Izmail was hit in the strikes. Izmail is on the Danube River that forms part of the Ukraine-Romania border.

A video showes explosions and a large fire in the distance on the Danube, captured by fishermen in Romania, a NATO member, on the other side of the river.

Three Ukrainian ports along the Danube are currently operating.

“The goal of the enemy was clearly the facilities of the ports and industrial infrastructure of the region,” Ukraine’s South operational command wrote in an update on Facebook. As a result of the attack, a fire broke out at industrial and port facilities, and a grain elevator was damaged.

Ukraine’s air force intercepted 23 Shahed drones over the country overnight, mostly in Odesa and Kyiv, according to a morning update.

All 10 drones fired at Kyiv were intercepted, said Serhii Popko, head of Kyiv City Administration. Numerous loud explosions were heard overnight as air defense systems were activated. Debris from felled drones hit three districts of the capital, damaging a nonresidential building, Popko said.