The passengers are reported to have been tourists on holiday in Sicily, and it is feared that those missing may have been trapped inside their cabins.
An 18-member crew had to be rescued from a life raft after their cargo ship was stricken by strong winds and 3.5 meters swells about 60 nautical miles west of Doringbaai.
Four people are confirmed dead, and the death toll is expected to rise, with hundreds of passengers still missing after a ferry carrying close to 500 people capsized in South Korea. Dramatic footage showing the search and rescue effort by the South Korean coast guard has been released.