A bridge partially collapsed early Friday in China's eastern city of Hangzhou, leaving a truck driver injured, police and witnesses said.

The collapse happened at around 2 a.m., leaving a 20-meter-long, 1-meter-wide pit in the right lane of the No. 3 Qiantang River Bridge, said a traffic police officer at the scene.

A passing heavy truck loaded with steel plates toppled off the bridge but its driver managed to jump from the vehicle before it plunged to the ground.

The injured driver was sent to a nearby hospital. Police said his condition was not critical.x Investigators said the truck was overloaded, as more than 100 tonnes of steel plates were collected from the scene, though the wreck of the vehicle weighed only 32 tonnes.

A resident who lives near the bridge said he heard two bangs and felt his home was shaking. "I thought it was an earthquake."

A surveillance camera showed that minutes before the cave-in, two trucks each loaded with over 100 tonnes of goods crossed the bridge, said a spokesman for Hangzhou municipal government at a press conference.

The bridge and several other roads leading to the bridge were closed after the accident. At 9:45 a.m., two-way traffic resumed on the left lane of the bridge, the spokesman said.

The No.3 Qiantang River Bridge, which opened in 1997, is an arterial road linking Hangzhou's downtown areas with the Xiaoshan International Airport, Binjiang Area and Xiaoshan Area.

Authorities said the bridge is off-limits to trucks.

However, the owner of the truck causing accident, who only gave his surname as Xu, said most truck drivers choose the No.3 Bridge although it is prohibited to trucks.

"Driving on the ring expressway is about 65 km from the city center to Xiaoshan Area, however, driving on No. 3 Qiantang River Bridge is 20 km less than going by the ring expressway," Xu said.