An explosion at or near a suspected nuclear facility near Tehran is being reported by Iran’s state news agency IRNA. The facility is described as an ‘explosives producing factory’ in eastern Tehran on Sunday evening. 

An opposition website claims the blast occurred near the Parchin military site, south-east of the capital, but there is no confirmation. The Parchin site, denied to international inspectors until reported by opposition groups, is thought to be a key component of Iran’s clandestine nuclear weapons program. Inspectors from the UN’s International Atomic Energy Agency (IAEA) have been denied access to the top secret facility since 2005.

Those familiar with Iran’s nuclear program have long believed Iran’s nuclear scientists have been conducting top secret experiments involving “high-explosive shaped charges with an inert core of depleted uranium” to test the characteristics of an implosion style nuclear device. An opposition group, The National Council of Resistance provided documentation to international inspectors that it claimed showed that Iran was developing a highly sophisticated network of underground tunnels at the Parchin site in order to advance its nuclear research away from prying eyes.