Head of Iran's Atomic Energy Organization Gholamreza Aghazadeh said on Tuesday that Iran plans to install 50,000 centrifuges, the official IRNA news agency reported.

"We have plans to install 50,000 centrifuges," Aghazadeh was quoted by IRNA as saying in an interview.

Asked about why he had not declared inauguration of 3,000 centrifuges at a ceremony held at Natanz on Monday to mark National Day of Nuclear Technology, he said he was concerned that mentioning numbers would cause ambiguity that Iran has plans for just 3,000 centrifuges.

"When we say we have entered industrial scale enrichment, (it means) there is no way back. Installation of centrifuges will continue steadily to reach a stage where all the 50,000 centrifuges are launched," he said.

"I was concerned the foreign media would misuse the issue and pretend that Iran's nuclear program would end up in installation of just 3,000 centrifuges," he added.

A senior Iranian nuclear official said on Monday that the number of operating centrifuges at the Natanz nuclear facility in central Iran would be known in 20 days.

"I don't think there's any need now to declare the number of centrifuges to which (UF6) gas has been injected, you should wait for the next 20 days when International Atomic Energy Agency (IAEA) inspectors present their reports," said Mohammad Saeedi, the deputy head of Iran's atomic energy organization.

Although the Iranian parliament has demanded the government reduce its cooperation with IAEA, inspectors from the UN atomic watchdog are still paying regular visits to Iranian nuclear sites.

Saeedi declined to comment on whether Iran's entry into the stage of fuel production on industrial scale meant injection of gas to 3,000 centrifuges, the report said.

When asked how many centrifuges are needed to start fuel production at the industrial level, Saeedi said, "We enter the industrial stage after passing the pilot stage."

Also on Monday, Larijani, when answering a question that if Iran had begun injecting gas into 3,000 centrifuges, said, "Yes, we have injected gas." But Larijani didn't explicitly say all the 3,000 machines had been installed.

Just a few minutes before Larijani's comments, Iranian President Mahmoud Ahmadinejad said Iran had become one of the few countries that could produce nuclear fuel at "industrial level", which was opposite to the UN demand of halting enrichment activities.

Some observers have predicted that Ahmadinejad's announcement, which was opposite to the UN resolution demand of halting enrichment, would escalate the current tension between Iran and the West, just five days after the end of sailors detention crisis with Britain.