At least one person has died.

The 136-meter-long Volgoneft 212 tanker, carrying 15 people, broke in half as the bow sank and waves swept over the deck, footage released by state media showed.

“There was a spill of oil products,” Russia’s water transport agency Rosmoreflot said.

The other Russian-flagged vessel, the 132-meter Volgoneft 239, was sailing after sustaining damage, the Emergencies Ministry said. It has a crew of 14 and was built in 1973.

Both tankers have a cargo capacity of about 4,200 tons.

Official statements did not provide details on the extent of the spill or why one of the tankers suffered such severe damage. The ships were in the Kerch Strait between mainland Russia and Crimea, which Russia annexed from Ukraine in 2014, when they sent out distress signals.

Russia said more than 50 people and equipment, including Mi-8 helicopters and rescue tugboats, had been deployed to the area.

The Russian newspaper Kommersant reported that the Volgoneft 212 tanker was carrying about 4,300 tons of fuel oil.

An unverified video posted on Telegram showed blackened water in rough seas and the tanker half-submerged.