Nine Syrian sailors are missing following a drone strike that sank a commercial ship off the coast of Bulgaria, a Syrian official told AFP on Thursday, after rescuers called off search operations.

Axar.az reports that Bulgarian authorities said no survivors had been found from the ship, after drones hit two commercial vessels early Tuesday in the Black Sea, the latest fallout from the Ukraine-Russia war in recent months.

The strikes caused one ship to catch fire, while the other sank.

According to the Maritime.bg specialized website, 10 people were aboard the sunken Togolese-flagged Alfa Watan.

Mazen Alloush, an official at Syria’s customs authority, told AFP that “the ship’s crew was composed of 10 sailors, nine of them Syrians and one Egyptian,” adding that “their fate is still unknown.”

He said Syria had sent urgent messages to the International Maritime Organization and to Bulgarian maritime authorities “calling for an independent and transparent investigation” into the incident.

They also demanded “the reasons that led to the suspension of search and rescue operations,” he added.

Eighteen Turkish and Indian crew members were rescued from the ship that caught fire.

Both commercial ships were managed by Turkiye-based companies, according to the Equasis merchant shipping database.