TEHRAN, Nov 18: Iran angrily denied on Thursday allegations by an exiled group that it was running a secret nuclear bomb facility near Tehran, and indicated that UN inspectors would be allowed to visit the site.

"We totally deny these allegations. This site is not a nuclear site and has nothing to do with our nuclear activities. Iran has no undeclared nuclear activities," top diplomat and nuclear negotiator Hossein Moussavian told AFP.

An Iranian opposition group, the National Council for Resistance in Iran, alleged this week that Iran is hiding a uranium enrichment facility near Tehran and aims to get the atomic bomb next year. But Mr Moussavian said Iran had already "declared all our nuclear sites and all our nuclear activities" to the International Atomic Energy Agency (IAEA).

"We have always responded positively to the agency's inspections requests. We have always cooperated," Mr Moussavian said when asked if IAEA inspectors could visit the alleged secret site. However, he also said that "it is not good for the agency to be played and manipulated by a well-known terrorist group".

The NCRI is the political arm of the Iraq-based People's Mujahideen, which the United States and the European Union consider a terrorist organization.

Iran has also come under fresh fire from the United States, with US Secretary of State Colin Powell saying on Wednesday that Washington had information that Iran is seeking to adapt its missiles to carry nuclear warheads.

"I have seen some information that would suggest that they've been actively working on delivery systems to deliver it," Mr Powell said.

In a related development, an Iranian judiciary official was quoted as saying that four people accused of spying on the country's nuclear programme for foreign governments have gone on trial.