Russia’s security service said early on Monday its border patrol boats had seized the Ukrainian naval vessels in the Black Sea and used weapons to force them to stop.
The FSB said it had been forced to act because the ships two small Ukrainian armoured artillery vessels and a tug boat had illegally entered its territorial waters, attempted illegal actions, and ignored warnings to stop while manoeuvring dangerously.
“Weapons were used with the aim of forcibly stopping the Ukrainian warships,” the FSB said in a statement circulated to Russian state media.
“As a result, all three Ukrainian naval vessels were seized in the Russian Federation’s territorial waters in the Black Sea.”
The FSB said three Ukrainian sailors were wounded in the incident and were getting medical care. Their lives were not in danger, it said.
With relations still raw after Russia’s annexation of Crimea and its backing for a pro-Moscow insurgency in eastern Ukraine, the incident risks pushing the two countries towards a wider conflict.
Ukraine denied its ships had done anything wrong, accused Russia of military aggression, and asked for the international community to mobilise to punish Russia.
The U.N. Security Council will meet on the latest developments at the request of Russia and Ukraine, diplomats said.
Ukrainian President Petro Poroshenko met his top military and security chiefs. Poroshenko said he would propose that parliament impose martial law.
Russia annexed Crimea in 2014 and then built a giant road bridge linking it to southern Russia that straddles the Kerch Strait a narrow stretch of water that links the Black Sea to the Sea of Azov, which is home to two of Ukraine’s most important ports.
Russia’s control of Crimea, where its Black Sea Fleet is based, and of the bridge mean it is able to control shipping flows.
The crisis began on Sunday after Russia stopped the three Ukrainian ships from entering the Sea of Azov by placing a cargo ship beneath the bridge.