TEHRAN Some two weeks ago the Atomic Energy Organization of Iran (AEOI) started installing and injecting gas into IR-6 centrifuges at the Fordow nuclear plant in line with its duties, AEOI spokesman Behrouz Kamalvandi announced on Sunday.Kamalvandi said the AEOI started injecting gas into 1000 IR-6 centrifuges, or six cascades of centrifuges, and this move had been announced to the International Atomic Energy Agency (IAEA) in advance.The IR-6 centrifuges have already produced uranium enriched to purity of 20 percent, Kamalvandi stated.Responding to foreign media outlets that Iran has increased its uranium stockpile, Kamalvandi said, Injecting gas into IR-6 centrifuges had been announced at least two weeks ago to the IAEA, and the IAEA had already announced it but foreign media outlets highlighted greatly with special purposes.