FILE PHOTO: A general view of the Bushehr main nuclear reactor, 1,200 km (746 miles) south of Tehran, August 21, 2010. Iran began fuelling its first nuclear power plant on Saturday, a potent symbol of its growing regional sway and rejection of international sanctions designed to prevent it building a nuclear bomb. REUTERS/Raheb Homavandi

LONDON (Reuters) - Iran has increased by fourfold the rate of production of low enriched uranium, an official in Natanz nuclear facility was cited as saying by Tasnim news agency on Monday, a week after Iran officially stopped some commitments under an international nuclear accord.

Under the agreement, Tehran was allowed to produce low-enriched uranium with a 300-kg limit. Tehran could ship the excess amounts out of the country for storage or sale.

Iran said this month the cap no longer applies as it scaled down commitments in reaction to U.S. unilateral withdrawal from the deal.

It was not clear how far Iran’s stock of low-enriched uranium was from the 300-kg limit. Under the deal Iran can enrich uranium at 3.67 percent, far below the 90 percent of weapons grade. It is also well below the 20 percent level to which Iran enriched uranium before the deal.