The death toll in a bus overturn Wednesday night in Shanghai has risen to 11 after another injured passenger died in hospital Thursday morning, according to the Shanghai Health Bureau.

The accident occurred at around 8:54 p.m. when the bus with 24 people on board turned over near the Longdong Avenue in Pudong District. Seven people were killed at the scene. By Thursday morning, four people died in hospital. Among 13 other injured passengers in hospital, one remained in critical condition, according to a spokesman with the bureau.

The injured passengers were rescued by police, firefighters and medics Wednesday night, and were rushed to two local hospitals.

The municipal information office said the bus is a shuttle bus of Inventec (Shanghai) Corporation. The victims are believed to be the company's employees.

Investigation into the accident is underway.