Five fishing-boat crew members are still missing after four were successfully rescued from the vessel, which capsized in stormy sea at the mouth of the Yangtze River on Nov 11.

The Shanghai Maritime Affairs Bureau said the boat, registered with Jiangsu province’s Qidong city, sank at 23:16 pm about 130 nautical miles to the northeast of the Yangtze River estuary. All nine people aboard were thrown into the sea, and four of them were rescued by nearby fishing vessels, the official said.

Patrol aircraft from the Shanghai Maritime Affairs Bureau arrived at 10:25 am Monday to search for the missing men but failed to find any. The search continued as the Donghai rescue bureau sent more professional rescue forces.

Bad weather was blamed for the accident. The Central Meteorological Station had issued yellow warning of strong winds at sea on both Nov 11 and 12 and advised fishing boats to go back to harbor.

"Similar accident happened in Jiangsu’s Yangkou Port (in water near Jiangsu’s Rudong) on early Sunday morning,” said Jin Zhirong, spokesman for Donghai No 1 Air Rescue Service. Jin said the rescue team received helpful information from Rao Liwei, the captain of a Liaoning Yingkou-registered fishing boat that was sinking at the time.

"We sent out helicopters to carry out rescue missions three times for that boat since 6:29 am (Sunday) and helped find one body,” said Jin. He said 12 crew members were on board at the time of that accident. Two bodies were reported found by Monday.

Jin said unlike typhoon warnings, which order fishing vessels to return to port, yellow warning of strong winds do not require ships to return.

"Winds coming from the east-west direction are extremely dangerous for boats sailing on the north-south routes, which was what happened to the fishing vessel near Yangkou Port,” he said.