At least seven people were killed and dozens injured after a fire engulfed a passenger bus in southern Nepal, police said Friday, according to dpa. Police said the bus caught on fire in Bara district, about 100 kilometres south of the capital Kathmandu, on Friday evening. At least 25 people were injured in the incident. The bus was heading from the town of Janakpur to Birgunj when the accident happened. The fire started from the middle of the bus trapping many passengers sitting at the rear. Many of the bodies were charred beyond recognition. Police said the cause of the accident was not immediately known. However, local media reports quoted witnesses as saying they heard the noise of an explosion shortly before the bus caught fire. Survivors said there was a heavy smell of petrol just before the fire started, suggesting arson. A group calling itself the Terai Army claimed responsibility for the blaze, saying it had carried out the arson attack because the bus had defied a general strike call in the region. The group had previously claimed responsibility for a triple blast in Kathmandu in September which killed three people. The police said they were investigating the incident although they refused to comment on the claim of responsibility.