Ukraine has imposed martial law for 30 days after Russia captured three of its vessels and 23 crew members.

The country's air force will partially mobilise under the measure, while authorities will also have the power to regulate the media and restrict public rallies.

President Petro Poroshenko asked Ukrainian MPs to back his motion for martial law after Russia opened fire on ships and captured three vessels in a major escalation of tensions off the coast of Crimea on Sunday.

Image: Ukrainian Defence Minister Stepan Poltorak (C) speaks to Ukrainian MPs before the vote on martial law

Six sailors were wounded after the Ukrainian navy said two artillery boats were hit by the strikes in the Black Sea.

Ukraine said its vessels were heading to the Sea of Azov in line with the international maritime rules.


Russia's Federal Security Service (FSB) said it used weapons after the Ukrainian ships ignored demands to stop, adding that it impounded three vessels which had illegally crossed the border.

Image: Seized Ukrainian ships, small armoured artillery ship and a tug boat, anchored in a port of Kerch, Ukraine

The injured sailors are receiving medical treatment and their lives are not in danger, the FSB said.

It was the first open military confrontation between the two neighbours since the annexation of Crimea in 2014.

Mr Poroshenko said martial law was necessary because of intelligence about "a highly serious threat of a ground operation against Ukraine."

"Martial law doesn't mean declaring a war. It is introduced with the sole purpose of boosting Ukraine's defence in the light of a growing aggression from Russia," he said.

Ukraine's defence ministry announced earlier in the day that its troops were on full combat alert in the country.

Some of Mr Poroshenko's critics reacted to his request for martial law with suspicion.

Oksana Syroid, a deputy speaker of parliament, noted that martial law was not introduced in 2014 or 2015 despite large-scale fighting in the east that has killed around 10,000 people.

Russian coast guard rams Ukrainian vessel

She said a state of emergency "would present a wonderful chance to manipulate the presidential elections."

NATO Secretary-General Jens Stoltenberg said Mr Poroshenko assured him that martial law would not have a negative impact on the election.

The president insists the move was necessary because what happened in the Kerch Strait between Crimea and the Russian mainland "was no accident", adding that "this was not the culmination of it yet."

Ukrainian Foreign Minister Pavlo Klimkin tweeted that Russia had engaged in "deliberately planned hostilities."

The FSB claimed it had "irrefutable evidence that Kiev prepared and orchestrated provocations".

Image: Russian jet fighters fly over a bridge connecting Russia with the Crimean peninsula

"These materials will soon be made public," it added.

Russian Foreign Minister Sergey Lavrov blamed Kiev for what he described as a "provocation", adding that Ukraine hoped that the US and Europe would take their side.

US Ambassador Nikki Haley subsequently urged Russia to "immediately cease its unlawful conduct" in the Black Sea.

US President Donald Trump said on Monday he does not like what is happening between Russia and Ukraine.

"We do not like what's happening either way. And hopefully it will get straightened out," Mr Trump told reporters as he left

the White House.

He said that European leaders were working on the situation, adding: "They're not thrilled. We're all working on it together."