Part of a runaway freight train has exploded in northeastern Iran, killing about 200 people - mostly firemen and rescue workers.
Officials say rescue workers were attempting to put out a fire on freight cars carrying fuel and industrial chemicals when the explosion occurred. The train cars had rolled away from a station and traveled out of control before they derailed, causing a fire and an explosion.
According to Iran's state-run news agency, the force of the blast caused serious damage to five villages near the town of Neyshapur, 650 kilometers east of the capital, Tehran.
The news agency said the freight cars were carrying fuel oil, sulphur and fertilizer.
Among those reported killed by the blast were the town's governor, mayor and fire chief.
Television footage showed fires burning in several mangled train cars, and black smoke billowing above the wreckage. The explosion was heard 75 kilometers away and was reported to have shattered windows within a radius of 10 kilometers.
Hundreds of injured people were transported to local hospitals.
Investigators are trying to determine what caused the tragedy.