A Turkish-flagged general cargo ship that was sailing on Thursday in the Black Sea en route to Ukraine's Izmail port did not sustain damage from an explosion, Turkey's maritime authority and the ship's captain told Reuters on Friday.

"An explosion occurred 15-20 meters behind the Kafkametler ship en route to Izmail port from Batumi port while it was cruising off the coast of Romania/Sulina (port)," the authority said.

The ship continued sailing to its destination to deliver its cargo following checks and there was no evidence that the explosion was caused by a mine, it added.

Maritime sources told Reuters on Thursday that the vessel had hit a sea mine and sustained minor damage, although the crew was safe.

The vessel's Istanbul-based operator Kafkametler Maritime said the vessel was currently on its way to Izmail port and ship congestion in the Danube channel meant it was moving slower. The company added that the crew were safe and the vessel did not need any maintenance.

The vessel's captain said separately in a statement that while the cause of the blast was not clear, the explosion appeared to have been caused by a bottom mine in the Black Sea.