Iranian officials say the death toll in Wednesday's train explosion has climbed to 295. Some 450 people were injured in the blast that occurred after a runaway freight train, carrying industrial chemicals, crashed and caught fire.
Iran has declared Thursday a national day of mourning, as residents near Neyshapur in a farming region of northeastern Iran prepared to bury their dead.
An emergency official said the scale of the devastation is greater than initially thought.
Rescue workers have pulled hundreds of bodies from the train wreckage and nearby villages that were flattened in the force of Wednesday's explosion.
The powerful explosion caused dozens of nearby houses to collapse, crushing the residents inside. The searing flames burned many bodies beyond recognition. Rescue teams were reported to be finding body parts hundreds of meters away from the site of the explosion.
The blast erupted after about 50 freight train cars, some carrying fuel oil, fertilizer and sulfur, rolled out of a station and derailed. Iranian seismologists recorded a 3.6 level tremor at the time of the blast.
Most of the dead are villagers, including the local governor and fire chief. Many firefighters who responded to the initial blazes were also killed in the explosion.
The United Nations has offered its condolences to the victims of the disaster, and has pledged to assist the survivors.