Six people are missing after a boat capsized on the upper Yangtze River early Tuesday, said local authorities Tuesday.

The sand-carrying vessel with six crew capsized when hit by a vehicle ferry in Fuling waters, southwest China's Chongqing Municipality, at 1:05 a.m., said Wu Mulin, of Chongqing Maritime Safety Administration.

A search for the missing was still underway, Wu said.

The administration is investigating the cause of the accident.