By Viktoria Lakezina

MYKOLAIV, Ukraine Russia attacked Odesa and Mykolaiv on Thursday in a third successive night of air strikes on southern Ukrainian port cities, wounding at least 21 people, Ukrainian officials said.

In Mykolaiv, several apartment buildings were left with charred fronts and gaping roofs. The entire top floor of one three-storey building had gone, and smoke rose from several other residential buildings.

Ukraine's military said Russian forces had launched 19 missiles and 19 drones overnight, and that five of the missiles and 13 of the drones had been shot down.

Mykolaiv regional governor Vitaliy Kim said 19 people had been wounded in the regional capital, Mykolaiv, and that several residential buildings had been damaged.

Odesa mayor Hennadiy Trukhanov said one person had been injured in the city, and that rescue workers were combing through the rubble in search of another person.

"I'm holding back my emotions, because they're over the edge," he said in a video posted online, standing inside what he said was a nursery damaged in the strike.

Russia has stepped up missile and drone attacks on Ukraine's Black Sea ports and surrounding areas since withdrawing on Monday from a year-old U.N.-brokered deal allowing the safe passage of Ukrainian grain shipments.

Ukraine is an important grain supplier and the deal was intended to help ease a global food crisis worsened by Russia's full-scale invasion last year.

Moscow did not comment on the latest air strikes but said attacks on Ukrainian port cities on Tuesday were retaliation for blasts on a bridge used to transport Russian military supplies which it blamed on Kyiv.

Andriy Yermak, head of Ukrainian President Volodymyr Zelenskiy's office, described the latest strikes as "Russian terror" and reiterated accusations that they were meant to disrupt food supplies to the Global South. Strikes early on Wednesday damaged port infrastructure, officials said.

"What we already know is that this is going to create a big and huge food crisis in the world", the European Union's foreign policy chief, Josep Borrell, said in Paris.

(Additional reporting by Dan Peleschuk and Olena Harmash in Kyiv, Editing by Timothy Heritage)