QINGDAO, Shandong - Heavy fog lingering for a week in East China's seaport of Qingdao, Shandong province, has disrupted passage on the waterway, stranding more than 200 vessels daily at the port, said the municipal marine affairs bureau on Tuesday.

The bureau launched a marine traffic control operation on Tuesday morning, as the fog reduced visibility to less than 50 meters at the port.

It sent alerts to passing vessels to avoid docking in Qingdao because the port can not accommodate any more vessels.

The bureau also said one person remains missing after a fishing boat from Liaoning province collided with a Shandong-registered cargo vessel near the port on Friday.