The death toll has risen to nine after a bus plunged into the Yangtze River in southwest China on Sunday, local authorities said Tuesday.

Divers found nine bodies and retrieved seven of them from the river in Chongqing Municipality as of 4:45 p.m. on Tuesday, according to the rescue headquarters.

Three bodies have been identified and another four are undergoing DNA analysis.

An investigation said that 15 people, including the bus driver, were involved in the crash.

The bus veered onto the wrong side of the road and collided into an oncoming car before breaking through road fencing and falling off a bridge in Wanzhou District on Sunday.

With the help of sonar technology and underwater robots, the bus was found 73 meters underwater, according to Zhou Dongrong, from Shanghai Salvage Co., a state-run salvage company.

However, water hazards and limited underwater visibility have hindered rescue efforts.