'Ranks of Zarqawi's terror network swell in Iraq'

His clandestine cell-structure stands alongside a separate revolt of 5,000 hardcore Sunni Muslim insurgents, motivated by communal aspirations and the politics of Saddam Hussein's Baath party, which can grow even larger in times of crisis, the official told AFP on condition of anonymity.

The two movements are separate, and contrary to claims by the Bush administration, Zarqawi and Saddam's followers have probably never mixed, the official said.

Zarqawi has poached members of the Kurdish Islamist faction Ansar al-Islam, which became active in late 2001, and shared headquarters with the al-Qaeda linked operative on Iraq's mountainous northeastern border with Iran before US air strikes destroyed their compounds in March 2003.

"There have been some number of defections of Ansar al-Islam individuals... The whole organisation is far less capable than it used to be. There are some numbers that have moved over and joined Zarqawi," the officer said.

"Zarqawi is a powerful man and his organisation has become pre-eminent. With power, (it) brings the desire of others to join the big guy."

Others small religious fundamentalist factions could also have linked up with Zarqawi.

"There are Iraqis who are part of the network. These are not Baathists. These are extremists," the officer said, using the military's shorthand for Sunni Muslim fundamentalists.