A cargo vessel is anchored at a container dock of the bonded port area in Qinzhou, south China's Guangxi Zhuang Autonomous Region, April 13, 2017. (Xinhua/Shen Hong)

MOSCOW, April 19 (Xinhua) -- A cargo ship with 12 crew members on board has sank in the Black Sea some 14 nautical miles (about 26 km) off Russia's coast, and so far only one crew member was rescued, the Russian Emergency Ministry said Wednesday.

The 114-m long vessel, Heroes of Arsenal, carrying the flag of Panama left the Russian port of Azov with a grain cargo and was on its way to Turkey, when the shipwreck occurred in the early hours of Wednesday, the ministry's Crimea division said in a statement.

The crew consisted of nine Ukrainians, two Russians and one Georgian, it said.

The ministry has started a rescue operation, but the fate of other crew members remained unknown. The statement said the operation was complicated by a storm raging in the region of the wreck.

Russian media quoted sources in law enforcement agencies in previous reports as saying that three members of the ship's crew had been rescued, but this has not been officially confirmed.