“The enemy has again attacked Odesa with a massive drone attack,” Oleh Kiper, governor of the region whose administrative centre is the city of Odesa, said on messaging app Telegram, though the full scale of the attack was not clear.

Ukraine’s air force usually reports details of overnight Russian attacks later in the morning.

In a Telegram post, Ukraine’s emergency service said three people were injured and several fires broke out in the city as a result of the attack.

Odesa’s mayor, Hennadiy Trukhanov, posted photographs depicting a residential building and other structures that had been nearly destroyed, while in others emergency workers sifted rubble and a dog peered from behind a pile of wood.

Reuters could not independently verify the reports.

There was no immediate comment from Russia.

Both sides deny targeting civilians in the war that Russia started with its full-scale invasion of Ukraine more than three years ago.

Late in March, the US said it had reached separate deals with Ukraine and Russia to pause their attacks over the Black Sea and against each other’s energy targets.

Both sides have repeatedly accused each other of breaking the moratoriums.