Greece has rescued all nine crew members, eight Turkish and one Azerbaijani, of a cargo ship that hit rocks and sank off the island of Andros early on Wednesday, a Greek coast guard official said.

The Vanuatu-flagged freighter had left Albania with hundreds of metric tons of soda on board and was bound for Ukraine when it sank off Andros, the coast guard official said.

It was not immediately clear what caused the cargo vessel, which was identified as Corsage C by the Marine Traffic ship tracker, to run aground.

A Greek shipping ministry official, who spoke on condition of anonymity, said there were no visible signs of pollution but two anti-pollution coast guard vessels and another two carrying anti-pollution equipment will preemptively deploy a sea barrier.

Two crew members were rescued from the sea and seven from a rocky area on Andros, the coast guard official said, adding that they had all been taken "in good health" to the island's clinic.

The ship's captain said all crew members were accounted for, the official added.

-Reporting by Angeliki Koutantou; Additional reporting by Yannis Souliotis; Editing by Kate Mayberry and Alexander Smith/Reuters