Chinese officials today said an initial probe into a fire in a crowded bus revealed \"serious criminal case\" and investigators suspects sabotage, as the death toll rose to 47. A rapid transit bus caught fire in the city of Xiamen in Fujian province while it was plying on an elevated bus lane yesterday, in one of the deadliest road accidents in the country recently. The death toll this morning rose to 47. Thirty four people were injured. The investigation by experts showed that the fire was caused yesterday by gasoline while the bus used diesel engine. A government official said the case was initially identified as a \"serious criminal case\" and further investigation is under way, state-run Xinhua news agency said. A working team led by State Councilor and Public Security Minister Guo Shengkun arrived in Xiamen today. After inspecting the scene and comforting the injured in hospitals, Guo asked experienced medical staff to expedite the rescue of injured and ensure all of them best treatment. The Public Security Ministry has urged local police departments to take rapid and effective measures to carry out a safety overhaul and ensure overall social stability.