SHANGHAI, Mar 21 (AP) -- A SUPERMARKET shuttle bus crashed into the side of a bridge onramp in Shanghai yesterday, injuring 33 passengers on the bus and blocking traffic for around an hour.

The accident happened at noon on the Pudong section of the Yangpu Bridge when the bus was trying to avoid a taxi that was trying to overtake it by speeding up and quickly changing lanes.

"We were moving at a high speed, and the bus driver couldn't respond properly to the sudden lane change," a witness passenger surnamed Ji told reporters from the news center of Shanghai Media Group yesterday.

The shuttle bus belongs to the French-owned Auchan Hypermarket's Changyang branch in Yangpu District, said the police.

Traffic police said the bus turned to the roadside to avoid the taxi, and that's when it slammed into the onramp and became stuck between two of the bridges beams.

All the injured were taken to hospital and are in stable condition, with the most severe injury being bone fractures, said the police.

The accident caused a traffic jam in the vicinity for at least an hour because the Yangpu Bridge is a key connection over the Huangpu River between Yangpu District and Pudong.