SARDIHA, India, (Agencies) Maoist rebels derailed a high-speed train packed with sleeping passengers into the path of a freight train in eastern India Friday, killing at least 100 people, police said. It was the latest in a series of deadly Maoist attacks that have put the govt under intense pressure to consider deploying the military as it struggles to contain the growing left-wing insurgency. Police warned the death toll would rise with dozens more bodies feared trapped in the mangled wreckage after 13 carriages of the Mumbai-bound express from Kolkata careened off the tracks in a remote area of West Bengal. Railways Minister Mamata Banerjee said the train had been derailed by a severe bomb blast, but officials said they were also looking at evidence that metal plates used to secure adjoining sections of track had been removed. It is a clear case of sabotage. The Maoists have done it, West Bengal police chief Bhupinder Singh told reporters at the crash site. He said Maoist leaflets had been found scattered by the tracks. The Press Trust of India said it had received a call claiming responsibility by the Maoist-backed Peoples Committee against Police Atrocities (PCPA), although a PCPA spokesman later contacted the news agency to deny the groups involvement. Police inspector general Surajit Kar Purakayastha, who was helping coordinate the rescue operation, said emergency teams had recovered 71 bodies. Were doing all we can, but Im afraid there are still more bodies trapped in some of the carriages, he told AFP. More than 200 people were reported injured, some of them in critical condition. Four of the carriages that slammed into an oncoming goods train were badly crushed and flipped on their sides with body parts clearly visible amid the twisted metal. Rescue workers with bolt cutters struggled to free anyone still alive inside. One survivor, Vinayak Sadna, said he had been sleeping when his carriage lurched violently to one side and then flipped over, flinging passengers around the compartment. I ended up stuck between two seats with an iron bar crushing my hand, Sadna said. I was trapped for three hours before I was pulled out. My wife is still missing. Another distraught passenger, Ranjit Ganguly, who was travelling to Mumbai for a holiday with his family, said he had been thrown from his carriage by the impact but his daughter and son were trapped inside. Paramedics treated the injured beside the track, while the most serious cases were evacuated by air force helicopters. The incident occurred at around 1:30 am (2000 GMT Thursday) in West Midnapore - a Maoist stronghold around 135 kilometres west of Kolkata. More than 80 passengers were taken to Kharagpur Railway Hospital where medical staff were overwhelmed by the number of wounded, some of them with serious head and spinal injuries. The Maoist rebellion, which Prime Minister Manmohan Singh has labelled the biggest threat to the countrys internal security, began in West Bengal in 1967 and has since spread to 20 of Indias 29 states. In April, the rebels ambushed and killed 76 policemen in the central state of Chhattisgarh.