Iranian officials say scores of people were killed Wednesday, when part of a freight train carrying fuel and chemicals derailed and exploded in the northeast of the country.
Iran's state news agency (IRNA) says at least 200 were killed and hundreds more were injured. But other officials said the death toll may be lower - between 50 and 60.
The accident happened in Khorasan Province.
The IRNA report says more than 50 railway cars derailed, causing a series of explosions near the city of Neyshapur. It says several homes along the tracks were destroyed.
According to the report, after the initial blasts, fire fighters rushed to control the blaze and more explosions occurred.
Iran's state television showed pictures of charred railway cars, with thick black smoke billowing into the sky.
The cars are reported to have been carrying gasoline, chemical fertilizers and sulfur products.