Sergeant Brian Sparks said the anger was fading but the memories were not, a typical reaction at the commemorations here in Iraq, where many have sacrificed long months and years away from families because of September 11, 2001.

"I was about to leave for Egypt when the terrorists struck, so we thought that our men would be the first on the frontline," he said.

"It didn't turn out that way, and I haven't seen my family for two years. Right now I'd like to be home," he said. "These people (Iraqis) are not terrorists, so where's the significance about being here."

Sparks is standing guard outside the gates of Baghdad International Airport, which the troops have dubbed "Biap".

Inside, the 8,000-strong 1st Armoured Division has set up base and hundreds are filing into the Bob Hope Dining Facility for a dawn memorial service, the first of about a dozen official ceremonies to be held around Iraq.

Among the crowd is 30-year-old airman Michael Passananti, whose father Horace died after two hijacked airliners struck the Twin Towers.

While Passananti, from the US Air Force, said he was was proud to be in Iraq and that the US military had made a difference in the war on terror by removing Saddam Hussein from power, he remained unconvinced the former dictator was linked to the attacks that killed his father.