China’s Consul General Chen Peijie, China’s top diplomat in Sabah, said the missing might be trapped by marine plants, fishing nets or debris, according to Xinhua News Agency.

“Please check carefully and look carefully for every possibility,” Chen is reported to have told First Admiral Adam Aziz, Kota Kinabalu director of the Malaysian Maritime Enforcement Agency.

The search and rescue operation expanded to 3,900 square nautical miles on Wednesday, up from Tuesday’s 3,000 square nautical miles.

It involves 350 personnel and 22 assets from the Malaysian navy, maritime authorities and the police as well neighboring Brunei, according to the report.

The catamaran, with 28 Chinese tourists and three crew members on board, capsized about 10am on Saturday after being battered by strong winds and high waves an hour after leaving the Tanjung Aru jetty here for Pulau Mengalum, 56km northwest of Kota Kinabalu.

Meanwhile, Chinese Ambassador to Malaysia Huang Huikang visited some Chinese tourists at Queen Elizabeth Hospital in Kota Kinabalu on Wednesday, where they were being treated for dehydration and severe sunburn.

“We will not give up any gleam of hope and will urge the Malaysian side to continue their search efforts and thoroughly investigate the incident so that tourists’ safety in Sabah can be ensured,” Xinhua quoted Huang as saying.