As we have gone on the offensive in former al Qaeda and insurgent sanctuaries, and as locals have increasingly supported our efforts, we have found a substantially increased the number of arms, ammunition and explosives caches.

CNN: Transcript of Iraq hearing statements

"I had a very clear view of them standing up with backpacks under them that also had additional ammunition and explosives and I could see them bending down and reaching in and getting things out of their backpacks, which included their explosives and their pressure-cooker bomb, " Mr Fitzenberg said.

BBC: Boston man who watched terror shoot-out from his home

The complex, south of Tehran, is dedicated to the research, and the development and production of ammunition, rockets and explosives.

BBC: Fresh Iran nuclear talks agreed with world powers - EU