Iran's official news agency is reporting that a blast caused by leftover ammunition has killed at least seven workers including foreign nationals at a steel mill in the central city of Yazd.
The Monday report by IRNA said the blast late Sunday wounded 12 other workers. It has not reported the nationality of the foreigners.
Local parliamentarian Ali Akbar Oliaw is quoted as blaming the blast on ammunition which arrived at the factory along with scrap metal.
Iran's media in the past has reported explosions which at first it said were caused by bombs, then in subsequent reports by stray ammunition.
Seventeen people were killed last month at a massive explosion at an ammunition dump near Tehran, which Iran has said was an accident.