Ukraine said Sunday that it had destroyed 22 Russian drones on the southern Odesa region, as Moscow said it hit the Danube port of Reni, on the border with NATO member Romania.

Russia has been targeting Ukrainian port infrastructure in the Odesa region for weeks, after exiting a deal that allowed safe passage for ships carrying grain from Ukrainian ports.

"On the night of September 3, 2023, the Russian occupiers launched several waves of attacks by 'Shahed-136/131' UAVs from the south and southeast," Ukraine's Air Force wrote on Telegram.

Twenty-five of the Iranian-made attack drones had been launched and "22 of them were destroyed by the forces and means of the Air Force in cooperation with the air defence of other components of the Defence Forces of Ukraine," it said.

But Ukrainian prosecutors said some of the drones hit the Danube area, saying that at least two people were wounded.

The Russian army said it had targeted "fuel storage facilities" in Reni, across the Danube river from NATO and EU member Romania.

Bucharest has condemned previous Russian attacks on Ukraine's Danube ports of Reni and Ismail.

Following the collapse in July of the United Nations-brokered deal allowing grain shipments from Black Sea ports, Russia has ramped up attacks on Ukraine's southern Odesa and Mykolaiv regions, home to ports and infrastructure vital for agriculture exports.

Last month the first civilian cargo ship sailing through the Black Sea from Ukraine arrived in Istanbul in defiance of the Russian blockade.

Ukrainian President Volodymyr Zelensky said on Saturday that two more vessels had passed through the country's "temporary Black Sea grain corridor".