Washington has again warned Iran against harbouring members of Osama Bin Laden's al-Qaeda network.

The new warning came after Tehran denied a US newspaper report that two key members of al-Qaeda were living on its territory along with dozens of fighters.

We have stated most recently... that there are some al-Qaeda in Iran

Scott McClellan White House spokesman

"We would call on and urge the Iranian Government not to offer any terrorists a safe haven," said White House spokesman Scott McClellan.

The Iranian Foreign Ministry earlier insisted that it was not Iran's policy to shelter al-Qaeda, blamed by the US for the 11 September terror attacks on America.

"We have stated most recently... that there are some al-Qaeda in Iran and, if there are, we expect every government not to harbour terrorists in their country and not to provide them with safe haven," said Mr McClellan, speaking from President George W Bush's ranch in Crawford, Texas.

"We want to be very clear to the Iranian Government on that message."

'Bin Laden's deputies'

The Washington Post's Wednesday edition quotes unnamed "Arab intelligence sources" as saying two al-Qaeda deputy leaders are now living inside the Iranian border.

Al-Qaeda has threatened more attacks

Saif al-Adel, an Egyptian, and Mahfouz Ould Walid are being sheltered along with al-Qaeda fighters in hotels and guesthouses in the border cities of Mashhad and Zabol, the daily says.

Mr al-Adel is on the most-wanted list of the US Federal Bureau of Investigation and both are regarded as being key al-Qaeda planners.

American officials had previously reported that Mr Walid - also known as "Abu Hafs the Mauritanian" - was killed near the Afghan city of Khost in January.

After the 11 September attacks on New York and Washington, the two men were put in command of al-Qaeda's military and ideological committees, the newspaper's sources said.

'Not in Iran'

Iran's Foreign Ministry said the newspaper report was "unfounded".

"These people are not in Iran, and certain American circles have got used to issuing and repeating such charges," said spokesman Hamid-Reza Asefi.

These are unfounded accusations - these people are not in Iran

Foreign ministry spokesman Hamid-Reza Asefi

Tehran, which supported the Northern Alliance against the Taleban and their al-Qaeda allies in Afghanistan, has consistently rejected US accusations that it is protecting militants who fled the US military campaign there.

It points to its transfer of 16 suspected al-Qaeda members to Saudi Arabia earlier in August.

In January, President George W Bush included Iran - together with North Korea and Iraq - in the "axis of evil" which he said was threatening international stability.

Earlier this month, Iranian President Mohammad Khatami criticised the US war on terror during a landmark visit to Afghanistan.

Analysts said the visit signalled a much closer relationship between Tehran and the new US-backed Afghan administration.