Rescuers search for the missing, July 29, 2016. [Photo/Xinhua]

CHONGQING - Four passengers are still missing after a boat capsized on a tributary of the Yangtze River in southwest China's Chongqing Municipality, said rescuers on Saturday.

They have pulled 10 people from the water so far. Rescue work is still under way.

The private boat capsized at about 5:40 p.m. Friday in Wushan County, where the Daning River meets the Yangtze, the Wushan County government said in a statement.

Local authorities previously said 12 were on board, before revising the number to 10, and then 14.

Boat owner Hu Wanbao, who was among the 10 rescued, is in custody for police investigation.

Rescuers, including five divers, are expanding their search area.

Investigation is under way. Survivors said it was not raining when the boat capsized, but the water level was high following recent flooding.

A thorough inspection was launched in Wushan County following the accident to crack down on illegal bus and boat services.