Dozens of people are feared dead after a packed train derailed in a tunnel in eastern Taiwan on Friday at the start of a long holiday weekend, with rescuers still scrambling to reach others trapped inside. Police said at least 49 people were classified as showing no signs of life when rescuers reached them in what looks likely to be the island's worst rail disaster in decades. A further 70 people were still thought to be trapped in carriages inside the tunnel while about 60 were taken to hospital. Officials said the accident could have been caused by a maintenance vehicle sliding down an embankment and striking the train before it entered the tunnel near the coastal city of Hualien. "There was a construction vehicle that didn't park properly and slid on to the rail track," Hualien county police chief Tsai Ding-hsien said. "This is our initial understanding and we are clarifying the cause of the incident," he said. Local media pictures from the scene showed the back of a yellow flatbed lorry on its side next to the train. President Tsai Ing-wen's office said she had ordered hospitals to prepare for a mass casualty event. "The top priority now is to rescue the stranded people," the president's office said. The accident occurred on Taiwan's eastern railway line at about 9.30am. Pictures published by local news website UDN showed the front of the train inside the tunnel had been pulverised into a twisted mesh of metal. The Central Emergency Operation Centre gave a lower suspected death toll, saying 26 people showed no signs of life. People farther back in the train were able to walk away from the crash comparatively unscathed. A live broadcast by UDN outside the tunnel showed a row of undamaged train carriages with rescuers helping passengers escape. "It felt like there was a sudden violent jolt and I found myself falling to the floor," an unidentified female survivor told the network, saying she suffered a cut to her head. "We broke the window to climb to the roof of the train to get out," she said. The eight-car train was travelling from Taipei to the south-eastern city of Taitung and was carrying about 350 passengers. The accident occurred at the start of the busy annual Tomb Sweeping Festival, a long holiday weekend when Taiwan's roads and railways are usually packed. During the festival, people return to ancestral villages to tidy up the graves of their relatives and make offerings. Taiwan's eastern railway line is usually a popular tourist draw down its scenic and less populated eastern coastline. With the help of tunnels and bridges, it winds its way through towering mountains and dramatic gorges before entering the picturesque Huadong Valley. <br/> The last major train derailment in Taiwan was in 2018, at the southern end of the same line, in which 18 people were killed. The driver of the eight-carriage train was later charged with negligent homicide. More than 200 of the 366 people on board were injured. That crash was the island's worst since 1991, when 30 passengers were killed and 112 injured after two trains collided in Miaoli. Thirty were also killed in 1981 after a lorry collided with a passenger train at a level crossing and sent coaches over a bridge in Hsinchu. And in 2003, 17 died and 156 were injured after a train on the Alishan mountain railway plunged into a chasm at the side of the track.