One person was presumed dead and five crew members reported missing on Sunday after a tug sank off South Africa's southern coast, a multi-agency maritime body said.
The tug Leo transmitted a distress message at 17:02 GMT on Saturday, reporting uncontrolled water ingress and requesting immediate assistance, South African Search and Rescue (SASAR) said in a statement.
The ship sank in the early hours of Sunday, approximately 80 nautical miles (148 kilometres) south of Mossel Bay in South Africa's Western Cape province.
"To date, 13 crew members have been accounted for, consisting of 12 survivors, and one presumed deceased," SASAR said, adding that the vessel had 18 crew members on board before the incident.
Search operations continue for the five missing crew members despite adverse weather conditions, SASAR said.
The Leo is a 73-metre offshore tug built in 1991. It was sailing under the flag of Comoros at the time of the incident.
(Reporting by Nelson Banya Editing by David Goodman, Baird Maritime)