Maoists blasted rail tracks in the eastern Indian West Midnapore district in the wee hours Friday, derailing 13 coaches of a Mumbai-bound express train, five of which were hit by a goods train, leaving 20 dead and 104 others injured, the second attack on civilians by Naxals this month. The blast occurred at 1:30 am when the Howrah-Kurla Lokmanya Tilak Gyaneshwari Super Deluxe Express was running between Khemasoli and Sardiya stations, about 135 km from here, South Eastern Railway officials were quoted as saying by the Press Trust of India. "We suspect Maoist hand behind the blast," Member (Traffic) Railway Board Vivek Sahai said, observing that the incident comes as Maoists are observing a 'black week'. He said the driver of the train heard a loud explosion after which the train derailed. Railways are investigating if the tracks were tinkered with, he said. Twenty of the bodies were extricated from the mangled coaches of the train after the 13 coaches derailed with five toppling over an adjacent track, Additional Superintendent of Police, Jhargram, Mukesh Kumar said. Indian Air Force helicopters have been pressed into service at the accident spot and have airlifted some of the injured to hospitals.