The head of Ukraine’s state security service (SBU) and other officials have revealed details of attacks on Ukrainian naval vessels by Russian troops in the Kerch Strait on November 25, 2018.

The incident started on Sunday when, three Ukrainian naval vessels, the military tug  “Jani Kapu” (A-947) and two small artillery boats Berdyansk (P-175) and Nikopol (P-176) strayed in the Kerch Strait, which connects the smaller Sea of Azov with the larger Black Sea. The ships were headed north from Odessa to Mariupol on the Sea of Azov.

Ukraine officials claim that its three warships were in waters shared by both countries under a 2003 agreement. It claims Russian border guard ships harassed and intimidated their ships, including ramming them and opening fire at least sixteen times. Ukraine says three of its sailors were seriously wounded and bleeding profusely in the incident.

In the evening on 25 November, Ukrainian vessels with 23 crew members been fired on and seized by the Russian troops in international waters.

“The real surprise is the fact that against the two Ukrainian boats and the small tugboat, the Russians used six “FSB” (Russian Federal Security Service) and four naval vessels, as well as combat helicopters and airplanes of the Russian Federation Air Force,” the head of Ukraine’s state security service (SBU) Vasyl Hrytsak said.

Russia also scrambled 5 fighter jets and two attacks helicopters to the Kerch area included modern Su-30 and Ka-52.

“According to the confirmed operational information of the SBU, one of the Russian attack aircraft used two unguided combat missiles against the Ukrainian boats, as a result of which one of the officers of the SBU was seriously wounded,” Vasyl Hrytsak also noted in a statement on Tuesday.

Russia confirmed it had used weapons to force the Ukrainian vessels to stop, saying three Ukrainians were injured.

Shots were fired at a small artillery boats Berdyansk (P-175), the boat was fired from a 30mm gun from the Russian ship and fired from a Su-30 fighter jet.

The tug was also was fired at, but the shells did not hit the target. Ukrainian ships were forced to stop, after which they were captured by Russian special forces.

The European Union called on Russia to “restore freedom of passage at the Kerch Strait” and urged “all to act with utmost restraint”.

Nato said it “fully supports Ukraine’s sovereignty and its territorial integrity, including its navigational rights in its territorial waters”. It said Russia should “ensure unhindered access to Ukrainian ports in the Azov Sea”.

Kyiv called Russia’s actions a flagrant violation of international law, because the Black Sea is free for shipping, and Crimea belongs to Ukraine.

On Monday, Ukrainian President Petro Poroshenko said he was proposing that parliament back a 30-day martial law.

Sunday’s clash is the first time Russia and Ukraine have come into open conflict in recent years, although Ukrainian forces have been fighting Russian-backed separatists and Russia volunteers in the east since 2014.