At least 11 people were killed and around 200 injured when a north-south express train was derailed in central Vietnam on Saturday, officials said. A nationwide broadcast of state-run Vietnam Television (VTV) showed two carriages that had been thrown off the track and left lying on the bank of a lake. Eight of the train's 13 carriages had been derailed, it said. "The train was running too fast," a Vietnamese witness said in the broadcast. "Shortly later we heard a loud sound. We ran and started breaking windows to get out the injured people." VTV said the military were using boats to rush the injured to hospitals in Hue city. Officials said around 200 survivors had been hurt. About 30 of the injured were in a critical condition, said railway officials and rescue workers in Phu Loc district in the central province of Thua Thien-Hue, 650 km (400 miles) south of Hanoi. It was not immediately clear whether any foreigners were among the casualties. Vietnam's north-south trains are popular with young Western travellers. Police and railway officials were investigating the cause of the accident. The train left Hanoi on Friday with 500 passengers and a crew of 29 on what would have been a 1,700-km (1,000-mile), 29-hour journey to the commercial southern hub Ho Chi Minh City. The accident blocked the line and brought other trains to a halt. An official from the state railway authority told VTV rescue workers were working to ensure traffic resumed on Sunday.