Russia has reportedly seized two Ukrainian navy ships in the Kerch Strait near Crimea after opening fire on the vessels, Ukraine has claimed.

The Ukrainian navy said in a statement posted to Facebook on Monday morning (Australian time) that two gunboats were captured and a tug was forced to stop.

It said two seamen were injured in the altercation.

Russia is yet to comment on the claims.

Earlier, Ukraine said a Russian coast guard vessel rammed a Ukrainian navy tugboat, resulting in damage to the ship’s engines and hull.

The incident took place on Sunday as three Ukrainian naval ships were transiting from Odessa on the Black Sea to Mariupol in the Sea of Azov, via the Kerch Strait.

Russia’s Federal Security Service (FSB) told Russian news agencies the Ukrainian ships held their course even though the area was temporarily closed.

“Their goal is clear, to create a conflict situation in the region.” the FSB said in a statement, which did not mention ramming the Ukrainian tugboat.

A spokesman for Ukrainian President Petro Poroshenko said that the leader is convening an emergency meeting of the military amid tensions with Russia near the Crimean Peninsula.

Although a 2003 treaty designates the Kerch Strait and Sea of Azov as shared territorial waters, Russia has been asserting greater control over the passage since 2015.

-with AAP