A boat carrying 31 people, including 28 Chinese tourists, has gone missing in the waters off Borneo island, the Malaysian Maritime Enforcement Agency said Sunday.
"The owner of the boat reported it missing on Saturday evening and we have begun a search and rescue mission," Awil Kamsari, a spokesman from the agency said.
In addition to the tourists, a skipper and two crew members were also on board when the boat sailed out on Saturday morning, the spokesman said, adding that weather conditions were bad on the day.
They were on their way to Pulau Mengalum, an island known for its pristine beaches and dive sites, west of Kota Kinabalu, the capital of Sabah state.
A statement by China's foreign ministry said "around 20" Chinese tourists were on the boat, while state television reported that its consulate in Sabah had confirmed that at least 18 Chinese nationals were on board.
An area of 400 nautical square miles is being searched with officers from the agency, the police, the navy and the airforce involved.
Malaysia navy chief Ahmad Kamarulzaman Ahmad Badaruddin tweeted that it was "so sad as it happened on CNY (Chinese New Year)" and said navy ships and a C130 aircraft were onsite for the search and rescue operation.
"I, like all the relatives of those on board, am hoping for progress in the search and rescue operation," Sabah's Tourism Minister Masidi Manjun told AFP.
"Our forces are trying their best."
However, bad weather conditions were hampering on-going search efforts, authorities said.
China's foreign ministry said that its consulate general in Kota Kinabalu had contacted Malaysian authorities and urged them to do all that they could to rescue the tourists.
This incident comes about a week after a boat tragedy in the southern Malaysian state of Johor.
Several bodies washed ashore at a beach near the east coast town of Mersing in Johor on Monday after a boat believed to be carrying some 40 Indonesian illegal immigrants capsized in rough seas.