An Iranian soldier wearing a gas mask during the Iran-Iraq War.

Explosions heard in the area west of Tehran Tuesday took place at the Raja-Shimi chemical industrial complex, which is affiliated with the Iranian Ministry of Defense and deals in the production of chemical materials for military use, the website Israel Defense has reported.

According to Israel Defense the complex in question has been suspected throughout the past decade of being part of an Iranian program for developing chemical weapons. Opposition officials have reported that considerable damage was done to the complex but the Iranian regime has claimed the explosions were a result of a controlled and planned detonation of old ammunition.

Israel Defense notes that the Iranian authorities used the same excuse following a November 2011 blast that rocked a military complex near the village of Bidganeh. Days later it was revealed that the blast took place at the center of a missile research plant which developed solid engine fuel for long-range surface-to-surface missiles. The blast, which was caused during an advanced solid engine fuel test,  resulted in the deaths of 17 people, including General Hassan Tehrani, the head of Iran’s missile program.