TUNIS (Reuters) - A merchant fuel ship heading from Equatorial Guinea to Malta sank off the coast of Gabes in Tunisia on Friday, two security sources told Reuters, adding that the navy rescued all seven crew members.

       The ship carried one thousand tons of fuel and sent a distress call seven miles away from Gabes to which the Tunisian navy responded, the sources added.

       The cause of the incident was bad weather, the environment ministry said, adding that water had seeped into the ship and reached a height of two metres.

       Authorities are working to avoid an environmental disaster and reduce repercussions, the ministry said in a statement.

       (Reporting by Tarek Amara; Writing by Alaa Swilam; Editing by Sandra Maler and Himani Sarkar)