London, Jan 12: A plot by Islamic terrorists to blow up the Eiffel Tower, which could have been the French 9/11, has been unearthed.

A scrambled short-wave radio conversation exposing the planned attack on the world's most visited monument was picked up by Portuguese air traffic controllers and passed on to French intelligence.

The 1,060 ft high tower has on an average more than 16,000 visitors a day and a successful strike on the iron tower could result in the loss of thousands of lives.

The plot was uncovered in a ''vague and muffled'' radio conversation picked up by air traffic controllers in Lisbon, the Daily Mail reported.

A police source close to France's DST intelligance agency said, ''It was a muffled conversation in Arabic that was passed on to us as a matter of course, but our analysts clearly identified the threat.''

''Security at the tower was already tight, but is now being stepped up.''

The plot comes in the wake of other threats made in recent days on the websites linked to Osama bin Laden's al Qaeda terror network, calling for the ''brothers of Islam to strike Paris.''