Police say too many passengers and driving too fast caused a bus accident that has now claimed 26 lives in Chongqing Municipality, southwest China, after two critically injured passenger succumbed to injuries.

A bus carrying 32 passengers, seven more than its allowable limit, ploughed through a guardrail of a bridge that spans a narrow gully. It was traveling on a road that runs parallel to the Jialing River on its way from Yubei District in downtown Chongqing to Beibei, in the suburbs of Chongqing, at 7:30 Monday morning.

The bus plunged 13 meters killing 22 passengers at the scene.

Two others died on the way to the hospital. Eight people were rushed to hospital where six, including the bus driver, are being treated for serious injuries.

Local traffic police are now blaming overloading and speeding as the main causes of the accident. They say the bus should not have been carrying more than 25 passengers. Police also say overnight rain may have caused the road to become slippery and contributed to the accident.

Government leaders, including Zhou Mubing, Chongqing's vice mayor in charge, are overseeing the rescue operation and handling the aftermath of the accident.

Last October a bus drove off the elevated on-ramp of a Chongqing bridge killing 30 people and injuring 20.