A boat carrying 31 persons aboard has lost contact with the authorities in Malaysia, an official said on Sunday.

It sailed from Kota Kinabalu in Sabah state on Saturday, and carried over 20 Chinese tourists, Xinhua news agency quoted the Consulate General of China as saying.

According to Malaysian Maritime Enforcement Agency, the boat was enroute to Pulau Mengalum, a popular tourist island 60 km west of Kota Kinabalu.

The agency has sent out ships and helicopters to the site for rescue operations. 

A maritime communications officer in Sabah said: "The search area covers 400 nautical square miles and involves waters between Kota Kinabalu and Pulau Mengalum."

It was not clear yet what caused the disappearance of the boat.