Blasts rocked two tankers from Russia’s shadow fleet in the Black Sea near Turkey’s Bosphorus strait on Friday, causing fires on the vessels, and rescue operations were launched for those on board, Turkish authorities and sources said.

The 274-meter-long tanker Kairos suffered an explosion and caught fire in the Black Sea while en route from Egypt to Russia, Turkey’s Transport Ministry said.

It said two fast rescue boats, a tugboat, and an emergency response vessel were immediately dispatched to the scene and the 25 crew members on board were safely rescued.

Kairos was heading to Russia’s Novorossiysk port when it reported “an external impact” causing a fire 28 nautical miles off the Turkish shore, Turkey’s Maritime Affairs Directorate said.

It said another tanker, Virat, was reportedly struck some 35 nautical miles offshore, further east in the Black Sea, and rescue units and a commercial vessel were sent to the scene.

Heavy smoke was detected in the engine room but the 20 personnel on board were in good condition, it added.

Both Kairos and Virat are on a list of ships subject to sanctions imposed against Russia following its full-scale invasion of Ukraine in 2022, according to LSEG data.

There have been incidents of ships hitting mines in the Black Sea in recent years and some mines have been found drifting.

The Kairos was sailing under the Gambian flag and in ballast when the incident occurred, Tribeca shipping agency said.

It said reports indicated that the ship may have struck a mine and be in danger of sinking.

Shipping traffic through the strait continued, the agency said.