The Ukrainian Navy said one its vessels had been hit and two sailors injured in the skirmishes near the Sea Of Azov. A spokesman said the small armoured artillery ship Berdyansk had lost power as a result of the attack. Russian warplanes and helicopters have been operating in the area today and the entry to the Sea of Azov via the Kerch Strait has been blocked by a huge cargo ship which has dropped anchor beneath a Russian-controlled bridge. There have been unconfirmed reports that three Ukrainian vessels have now been seized by Russian special forces.
Ukrainian President Petro Poroshenko has called an emergency war cabinet meeting to discuss the Black Sea clashes.
Defence officials in Kiev had earlier accused the Russians of deliberately ramming a tugboat.
They said the ”openly aggressive actions” took place as three of its vessels sailed from the Black Sea port of Odessa to Mariupol in the Sea of Azov.
The Ukrainian navy said its tugboat Yana Kapu suffered damage to its engine, guard rail and outer shell when it was deliberately rammed by a Russian navy vessel.
Russia said the Ukrainian vessels – two small warships named as the Berdyansk and the Nikopol, and the tug – were trying “to create a conflict situation in this region” after they left Odessa.
Officials said the ships “illegally entered a temporarily closed area of Russian territorial waters”.
But Ukraine said it had informed the Russians of its plan to move its ships through the sea to Mariupol.
Politicians in Moscow said Ukraine was tyring to provoke Russia in an attempt to win military support from the European Union and NATO.
Konstantin Kosachev, chairman of the international committee of Russia’s Federation Council upper house, said: “A provocation of the Ukrainian military is unfolding in the Kerch Strait before our eyes.
“No doubt it has been ventured with the only goal – to force Russia to stop this provocation and picture Russia’s reaction as aggression
“It is an absolutely senseless idea from the military point of view. But, regrettably, it is a rather promising idea from the political point of view: both NATO and the European Union are sure to stand up for Kiev’s provokers, no matter what happens.”
And the head of the Republic of Crimea, Sergei Aksyonov, also blamed the US and Europe of for the “provocations”.
He said: “Today, Ukrainian warships illegally crossed Russia’s border and blatantly violated norms of international law.
“I am sure Western patrons of the Kiev regime are behind this provocation – it doesn’t look a mere coincidence that European and American politicians have been so concerned over the situation in the Sea of Azov in the recent months.
“Ukraine, as a country stripped of sovereignty and being under external governance, is an instrument for whipping up international tensions.”
Tensions have been rising in the seas off the Crimean peninsula, which was annexed by Russia in 2014, over the last few months and a Russian FSB security service official said Ukraine had sent naval reinforcements to the area.
Russia has recently increased its military presence and inspections, with some calling its actions an “economic blockade” of Ukraine’s Azov ports in the east of the country.
More than 10,000 people have died in the eastern Donetsk and Luhansk region since separatists moved against the Ukrainian state in April 2014.
Ukraine and the West accuse Russia of sending its troops to the region and arming the separatists.
Moscow denies this, but admits that Russian “volunteers” are helping the rebels.