Russia has mounted a third straight night of air strikes on Ukrainian ports, which set buildings ablaze and damaged China’s consulate in Odesa.

At least 27 civilians were reported hurt in the strikes.

In its most explicit threat yet, Russia’s military also announced it would deem all ships heading for Ukrainian waters to be potentially carrying weapons, and their flag countries as parties to the war on the Ukrainian side.

It said it was declaring parts of the Black Sea to be unsafe.

Ukraine responded on Thursday by announcing similar measures, saying it would consider vessels bound for Russia or Russian-occupied Ukrainian territory also to be carrying arms.

Ukraine’s President Volodymyr Zelensky said on Telegram that he had spoken to Ethiopia’s Prime Minister Abiy Ahmed and told him Ukraine was still ready to remain a guarantor of global food security.

The US said the warning indicated it might attack vessels at sea following the Russian withdrawal this week from a United Nations brokered deal to let Ukraine export grain.

The signals that Russia was willing to use force to reimpose its blockade of one of the world’s biggest food exporters set global prices soaring.

Russia says it will not participate in the year-old grain deal without better terms for its own food and fertiliser sales.

The UN Security Council will meet on Friday over “the humanitarian consequences” of Russia’s withdrawal, Britain’s UN mission said.

Ukraine hopes to resume exports without Russia’s participation.
But no ships have sailed from its ports since Russia pulled out of the deal on Monday, and insurers have had doubts about whether to underwrite policies for trade in a war zone.

Since quitting the deal, Russia has rained missiles down nightly on Ukraine’s two biggest port cities Odesa and Mykolaiv.

Odesa regional governor Oleh Kiper posted an image online of China’s consulate building with broken windows.

It is in Odesa’s city centre, just across railway tracks from the port.

“The aggressor is deliberately hitting the port infrastructure – administrative and residential buildings nearby were damaged… It shows the enemy does not pay attention to anything,” Mr Kiper said on Telegram.

The Chinese foreign ministry said the shock wave of the explosion “knocked down parts of the walls and window panes of the consulate … China is paying close attention to the relevant developments.”

In Mykolaiv, firefighters battled a huge blaze at a pink stucco residential building, blasted into a ruin. Several other residential buildings were also damaged.

Russia has described the port attacks as revenge for a Ukrainian strike on its bridge to Crimea on Monday.

It said on Thursday its retaliatory strikes were continuing and it had hit all its targets in Odesa and Mykolaiv.

The escalation comes as Ukraine reports an attempt by Russia to return to the offensive in the north-east of Ukraine, where it says 100,000 Russian troops and hundreds of tanks are being used.

On the front line near Kupiansk, a railway hub Ukraine recaptured last month, Stanislav, an artillery unit commander, said his forces had received newly issued cluster munitions, and could start firing them soon: “Maybe today or tomorrow”.

The US started sending Ukraine cluster munitions this month, although many countries have banned them as a potential danger to civilians.

Ukraine says the munitions, which contain scores of small bomblets that rain shrapnel over an area, could save lives if used in narrow circumstances to hasten the collapse of Russia’s front line.

Since last month, Ukrainian forces have been on the march in the east and the south recapturing small amounts of territory.

But the going has been slow, with the Ukrainian forces yet to take on Russia’s main defensive lines.

-AAP