Waves as high as 2.5 metres may have caused a barge to capsize with 14 of its crew members still missing off Tanjung Pungai, Pengerang this morning.

READ ALSO: Barge with Chinese nationals sinks off Timur Tanjung Punggai

Tanjung Sedili operations director of the Malaysian Maritime Enforcement Agency (MMEA), Commander Mustafa Kamal Abas said such strong waves could cause the barge to topple as it was carrying a big load.

"We believe the crew members were trapped under the barge as they were believed to be fast asleep at the time," he told a press conference in Tanjung Sedili today.

Until this afternoon, only one crew member, chief engineer Li Guozheng, 51, from Zhenjiang, China was rescued in the 4.20am incident.

The barge was believed to be carrying a load of sand from Teluk Ramunia towards Pengerang when it was hit by waves and capsized.

Mustafa said the search and rescue operation had been extended by five nautical miles from the incident area, 8.6 nautical miles from Tanjung Punggai.

"The search operation was difficult as the sea was rough. However, we continued until 7.30pm before calling it off and will start again at 6am tomorrow."

The search involved over 20 members of MMEA, Marine Operations Force and the Royal Malaysian Navy supported by four boats, one vessel and a Dauphene 365 aircraft.

READ ALSO: Maritime authority conducts SAR operations for capsized barge

List of 14 missing crew:

Chinese nationals

1) Liang Miaogui, 48, from Zhenjiang - barge skipper
2) Wang Fuling, 51, from Zhenjiang - head of operations
3) Li Wangping, 28, from Zhejiang - crew
4) Wang Youshi, 43, from Hubei - crew
5) Jlang Xuewen (he), 49, from Hubei - crew
6) Luo Bangguo, 50, from Zhenjiang - crew
7) Fan Qile, 44, from Hubei - crew
8) Jin Liangbong, 50, from Zhenjiang - crew
9) Xu Jiabao, 46, from Hubei - crew
10) Wang Yunfeng, 39, from Hubei - crew
11) Xu Huawei, 50, from Hubei - crew
12) Sun Shoutan, 40, from Shandong - crew
13) Liu Chuihua, 51, from Hubei - cook

Malaysian:

1) Raja Mohammad Firdaus, 23, from Selangor - communications officer