A search for 7 fishermen who disappeared after their boat sank off the coast of Shanghai was continuing on Monday, authorities said.

The city's Maritime Safety Administration lost contact with the 17-meter-long? wooden vessel the Hunanyu 400160 when it was about 6 nautical miles off Nanhui district at 6:57 pm on Sunday, Xinhua News Agency reported.

The administration said the boat was scheduled to dock before 6:30 pm, but the last time it heard from the boat was at 7:30 am when it arrived in the fishing area.

Patrol boats, aircraft and a towboat were sent to search for the sailors but failed to find anyone.

"We didn't find any remains of the boat, let alone the fishermen," said Pan Jiepei, spokeswoman for the administration, adding that three rescue boats were still searching for survivors on Monday.

Jin Zhirong, spokesman for the Donghai No 1 Air Rescue Service, told China Daily on Monday afternoon: "Visibility? is less than 3 kilometers on the sea at the moment. We're waiting for the wind to disperse the thick clouds."

The Maritime Safety Administration issued a strong-wind warning for small vessels on micro blog site Sina Weibo on Monday morning.