MASHHAD, Feb 18: Nearly 295 people are feared to have been killed and hundreds injured on Wednesday after runaway rail wagons loaded with an explosive cocktail of sulphur , petrol and fertilizer derailed and blew up in north east Iran, local officials said.

The cargo exploded as fire fighters, watched by curious villagers, were attempting to douse a blaze which broke out after the string of dozens of wagons came off the tracks at Khayyam station.

"Up to now, accurate reports say 182 people are dead and 350 injured," Mohammad Maghdori, a deputy governor-general of Khorassan province and chief of emergencies, told state television. The head of Khorassan province's disasters unit, Vahid Barakchi, earlier told Irna news agency that the death toll stood at "more than 200".

"The explosion happened at a time when the fire fighters and the rescue workers were trying to put out the fire, and a number of the fire fighters and local villagers were killed in the explosion," Mr Barakchi added.

Television pictures showed smashed, blackened and burning tank wagons and other rolling stock piled up on the tracks as firemen hosed the wreckage. Mr Barakchi said the fire was eventually extinguished.

A report said the blast was heard as far as the provincial capital of Mashhad, nearly 75 kilometres away. Surrounding villages suffered serious damage, with three helicopters sent into the area to help scores of ambulances evacuate the wounded.

Officials said police and Revolutionary Guards had sealed off the site due to the risk of further explosions and a possible health hazard from the fumes. Sabotage, however, appears to have been ruled out, and Transport Minister Ahmad Khoram has already arrived in the disaster area.

Local officials said the rail wagons, which were parked in a nearby station, began rolling away in the early hours of the morning, possibly after being jolted by a light earthquake.

After racing out of control, the 51 wagons then derailed and a fire erupted with several minor explosions reported, drawing fire fighters and locals to the scene. -AFP