Iran's Fars news agency reported on Monday that the cause of the blast late on Sunday was not immediately clear, but Fars said a large number of gas canisters used in homes for cooking had exploded.

"It is not yet clear if [the blast] was intentional or not," Fars reported, adding that the explosion occurred at a gas company in a suburb of Karaj, west of Tehran.

"The number of probable deaths in the explosion has been put at 15," Fars reported without giving more details.

Agencies