The driver of a double-decker bus that toppled over in Hong Kong killing at least 18 people and injuring more than 50 others on Saturday evening has been arrested for dangerous driving, police said.Images from the scene showed rescuers attempting to reach passengers trapped inside the bus, which lay on its side with part of its roof torn off by a road near the town of Tai Po in the northern New Territories.It appeared to have slid on its side and hit a lamppost which smashed into the front of the vehicle.The dead included 15 males and three females, police said, revising down their earlier toll of 19 killed at the scene. The driver has been arrested on two counts of causing death and grievous bodily harm by dangerous driving.Authorities said 10 of the injured are in a critical condition, with at least another 44 still in hospital. They were unable to say if any passengers were still inside the bus.It was not immediately known what caused the accident but passengers quoted by local media said the driver was going fast before the crash."It was much faster than I normally felt in a bus," an injured passenger told the South China Morning Post's online edition."And then it was like the tyre slipped, and the bus turned. It was really chaotic in the bus. People fell on one another and got tossed from side to side," he said.Passengers had complained to the driver who was reportedly 10 minutes late and he then kept speeding up before the bus crashed, the Apple Daily reported, quoting injured passengers at the scene."(The driver was) intentionally using the bus to throw a tantrum," another injured passenger told the Oriental Daily.Lawmaker Lam Cheuk-ting of the Democratic Party urged the government to investigate bus designs, "especially with the upper deck of buses having been repeatedly torn off in accidents, posing a serious threat to passengers on the upper level".The southern Chinese city promotes its public transport system as one of the best infrastructures in the world but fatal accidents do occasionally happen.