NEYSHABUR, 20 February 2004 — Grieving villagers were yesterday trying to retrieve the body parts of their relatives who perished in a massive explosion in this northeastern Iranian city a day earlier. President Mohammad Khatami ordered a tough investigation into how railway wagons loaded with highly explosive cargoes managed to run away and explode, as the death toll rose to 320.

Describing Wednesday’s freak disaster as “sad and unacceptable”, the president ordered “full light to be shed on the causes of the accident”, the official news agency IRNA said.

“I hope that with more attention and responsibility we will no longer witness such sad and unacceptable accidents,” said Khatami, as recovery teams and mechanical diggers began clearing away the blackened wreckage of the wagons.

Negligence or a brake failure probably caused the 51 train cars to roll down the track until they derailed and exploded, the provincial governor said. “One possible cause is negligence of the personnel at the station and the other is technical failure of the braking system,” Khorasan province Gov. Hassan Rasouli said.

Individual cars have brakes and an iron wedge is used as something like a large doorstop beneath the lead car, Rasouli explained. “What we do know is that the brake that is put in front of the cars was broken,” he said, adding that he did not know if the other brakes were functioning.

The provincial head of the Iranian Red Crescent, Seyed Ali Hosseini, gave the new toll of 320 dead and 460 injured, adding, “It is possible that there are more bodies under the wreckage.” He said that recovery teams still had to search through a crater 150 meters in diameter and 20 meters deep.

Inconsolable mothers sifted through charred bodies, trying to find enough of their loved ones for a fitting burial. The grim stench of unclaimed bodies pervaded the cemetery in the town, where limbless torsos and scraps of flesh scorched black by the blast were laid out on plastic sheeting.

The thunderous blast was felt 70 km away. It disintegrated mud brick houses nearby and forced many villagers to move into camps.

Through the night, Revolutionary Guards had maintained a one-km cordon around the disaster site, fearing three unexploded gasoline wagons could still blow up.

But at dawn, with thin plumes of white smoke still rising from the wreckage, officials said the danger had passed.

The deadly mix of cargoes — sulfur, fertilizer, petrol and cotton — the train was carrying is likely to raise tough questions over rail transport safety. IRNA reported that nearby railway station managers had been called in for questioning.

Although the alert level around the wreckage has been lowered, the station remained sealed off by members of the Revolutionary Guards.

— Additional input from agencies