The UN Security Council will hold an emergency meeting on Monday to discuss rising tension between Ukraineinfo-icon and Russiainfo-icon after the seizure of three Ukrainian Navy ships in the Kerch Strait on Sunday.

The Kerch Strait is a narrow waterway leading to the Sea of Azov, which has been increasingly controlled by Russia since the conflictinfo-icon over Crimea erupted in 2014.

On Sunday, two Ukrainian Navy gunboats and a tugboat were reportedly fired upon by a Russian Border Guard vessel. Russia claimed the three Ukrainian Navy ships had entered its waters illegally. Ukraine claimed six of its personnel were injured in the incident, while Russia claimed only three men had sustained minor injuries.

In a related development, Ukrainian President Petro Poroshenko late on Sunday asked the country's parliament to vote Monday on whether to impose martial law in the country for 60 days given the Kerch Strait incident. Calling the attack on the Ukrainian Navy ships a "deliberate action", Poroshenko claimed the imposition of martial law did not mean Ukraine would resort to "any offensive actions".

The European Unioninfo-icon and NATO called for de-escalation of the situation in the Kerch Strait and demanded Russia restore freedom of passage in the Sea of Azov.

Ukraine had been complaining of increased Russian activity in the Sea of Azov since 2014, which had resulted in harassment of its ships and checks on merchant vessels sailing to Ukrainian ports.