Updated at 2.31pm: A 50-year-old man was killed after being knocked down and trapped by a reversing tractor in Sha Tin, police said on Thursday. A spokesman said the accident occurred about 10.20am. The tractor, driven by a 54-year-old man, reportedly hit the 50-year-old man while it was reversing inside the open area of Sha Tin Refuse Transfer Station on On Hing Lane. After the impact, the man was trapped underneath the tractor. He was certified dead at the scene, the spokesman said. Investigations by the Special Investigation Team of Traffic, New Territories South are continuing. The spokesman urged witnesses to the accident or people with information to call officers on tel: 3661-1344. The tractor accident came amid a spate of fatal accidents in Hong Kong involving reversing trucks, in which four people have died in the past two months. The government is planning new restrictions on the use of some roads ? particularly narrow cul-de-sacs ? and is requiring additional safety equipment for goods vehicles in response to such accidents.