CHENGDU - Sixteen people, including 11 students, have been confirmed dead in a Sunday road accident in Southwest China's Sichuan province, local authorities said.

The accident occurred at 2 pm in Zhenwu Village in Quxian County, Dazhou City, when a passenger bus collided with a heavy-duty truck loaded with sand and cobblestones. The bus plunged into a three-meter-deep riverbed, the Dazhou emergency response office said in a statement.

The bus with 24 people aboard, including 12 students, was then buried by sand and cobblestones from the overturned truck.

Of the 25 people including a truck driver, sixteen were killed, and four, including a student, were in serious condition, the statement said.

The cause of the accident is under investigation.