The US forces recognised his face, and knew they had the leader of al-Qaeda in Iraq.

Initially, the US military had said al-Zarqawi was killed outright. But this weekend new details emerged of his final moments.

For three years, Zarqawi orchestrated horrific acts of violence guided by his extremist vision of jihad, or holy war . . . first against the US soldiers he considered occupiers of Arab lands, then against the Shiites he considered infidels.

On Wednesday, the US military tracked him to a house northwest of Baghdad, and blew it up with two 500 pound bombs.

Zarqawi somehow managed to survive the impact of the bombs, weapons so powerful they tore a huge crater in the date palm forest where the house was nestled just outside the town of Baquba.

Iraqi police reached the scene first, and found the 39-year-old Zarqawi alive.

"He mumbled something, but it was indistinguishable and it was very short, " Maj Gen William Caldwell, spokesman for US-led forces in Iraq, said of the Jordanian-born insurgent's last words.

Iraqi police pulled him from the flattened home and placed him on a makeshift stretcher. US troops arrived, saw that Zarqawi was conscious, and tried to provide medical treatment, the spokesman said.

"He obviously had some kind of visual recognition of who they were because he attempted to roll off the stretcher, as I am told, and get away, realising it was the US military, " Caldwell told Pentagon reporters via video conference from Baghdad.

Zarqawi "attempted to, sort of, turn away off the stretcher, " he said.

"Everybody re-secured him back onto the stretcher, but he died almost immediately thereafter from the wounds he'd received from this air strike."

So much blood covered Zarqawi's body that US forces cleaned him up before taking photographs. "Despite the fact that this person actually had no regard for human life, we were not going to treat him in the same manner, " Caldwell said.

The air strike killed two other men and three women who were in the house, but only Zarqawi and his spiritual adviser have been positively identified, he said.

Caldwell also said experts told him it is not unheard of for people to survive a blast of that magnitude.

"There are cases when people, in fact, can survive even an attack like that on a building structure.

Obviously, the other five in the building did not, but he did for some reason, " Caldwell said.

He said he did not know if Zarqawi was inside or outside the house when the bombs struck.

"Well, what we had found, as with anything, first reports are not always fully accurate as we continue the debriefings.

"But we were not aware yesterday that, in fact, Zarqawi was alive when US forces arrived on the site, " Caldwell said.

His recounting of the aftermath of the airstrike could not be independently verified. The Iraqi government confirmed only that Iraqi forces were first on the scene, followed by the Americans.

An aide to Prime Minister Nouri Maliki, who asked for anonymity, said he saw Caldwell's news briefing but could neither confirm nor deny that Zarqawi briefly survived the blast.

"Well, I think it's clear: The Americans said he was seriously wounded and he died, " the aide said.