Iran confirmed on Monday the start of uranium enrichment at its underground Fordow nuclear plant, Iran's Arabic language al Alam TV reported.

All of Iran's nuclear activities, including enrichment of uranium in both Natanz and Fordow nuclear sites are under supervision of the International Atomic Energy Agency (IAEA), Iran's envoy to the agency Ali Asghar Soltanieh told al Alam.

Diplomatic sources told Reuters in Vienna that Iran had started refining uranium in Fordow.

(Writing by Parisa Hafezi)