Twenty-five people have been rescued after a boat carrying Chinese tourists sank in rough seas off the coast of Malaysia. Officials have said that six people are still missing.

The boat sank on Saturday (28 January) on route to Pulau Mengalum, a popular location for tourists, the BBC reported. It had sent out a distress call but contact was soon lost.

When the boat did not reach its destination, authorities were alerted and a search operation covering 400 nautical square miles began. "We will deploy search assets that can operate at night, and continue our rescue operations to locate those who are still missing," a national security minister told press.

Twenty-eight of those on board were Chinese tourists while its two crew members and the captain were all from Malaysia. Eighteen of the tourists were found by fishermen and five by a tug boat. The captain and one of the crew members had swum to safety to a nearby island where they were rescued.

The vessel reportedly hit rough seas, which led to its sinking. The head of the Malaysian Maritime Enforcement Agency said, "According to the skipper, the boat was 'broken' after being hit by waves and sank." The same rough seas then made the search operation more difficult.

Chinese news agencies reported that President Xi Jinping had asked Malaysia for "all-out search and rescue efforts".

Medics attend survivors of Malaysia boat sinking
Medics attend to survivors at a jetty in Kota Kinabalu Getty