Hundreds of passengers travelling to Lhasa were stranded for more than five hours yesterday when a dining car on the Qinghai-Tibet railway became detached. The incident was the first mishap on the rail system since it began operating two months ago. It occurred at around noon as the train, out of Chongqing , approached a station at Tsona Lake. Xinhua said the dining car became detached and that malfunctioning signalling and switching equipment were to blame. No passengers were hurt. The train resumed its trip at 6pm, the report said. It was unclear if the dining car was towed to the station or reconnected. Official media did not give details of disruptions to schedules, but passengers on other trains on the same line said their trains were delayed for hours. At Amdo station, to the north, at least two trains carrying hundreds of passengers had to wait hours for services to resume. Hong Kong executive councillor Leung Chun-ying, who was on a Better Hong Kong Foundation tour, said the train captain informed passengers of the incident shortly after dinner at 5.30pm. His train was stranded in Amdo for about five hours before resuming its journey at around 10.30pm. 'Everything is fine with us. We just chatted with each other when the train was stranded,' Mr Leung said from Amdo. He said the group had not suffered from altitude sickness, although members of his party sometimes had to turn on the oxygen supply. He said he expected to arrive in Lhasa at around 3am. The central government has hailed the construction of the railway as an engineering marvel. Tibetan officials recently said the railway line would be extended to China's border with Nepal. Since it started operation on July 1, the 1,142km line from Golmud in Qinghai to Lhasa in Tibet has transported more than 270,000 people, according to chief railway co-ordinator Zhang Xiqing .