Witnesses said they saw a US plane fire two missiles on the residential Shuhada district in the south of the city, 50 kilometres (30 miles) west of Baghdad, but the local hospital said it had only received two injured people.

"Today, coalition forces conducted another strike on a known Zarqawi network safe house in southeastern Fallujah, based on multiple confirmations of Iraqi and coalition intelligence," the coalition's deputy director of operations, Brigadier General Mark Kimmitt, said in a statement.

"This operation employed precision weapons to target and destroy the safe house," he added.

A senior military official said between 20 and 25 people were killed in the attack, which was along the same lines as two other airborne missile strikes on suspected Zarkawi hideouts in Fallujah over the past week.

The total death toll from the three raids is 59 to 64 people, the US military said, warning that it would not shrink from carrying out further such strikes.

"Wherever and whenever we find elements of the Zarqawi network, we will attack them," Kimmitt said.

But the airstrikes left behind a shell-shocked city.

"A US aircraft fired what looked to be two missiles on the house" in Shuhada, local resident Ayman Ibrahim told AFP.

His claim was backed up by another resident, who asked to remain anonymous.

A leading sheikh, Abdallah Janabi, condemning the attacks as launched "under the pretext that Zarqawi is based in Fallujah."

"There are no foreign fighters here", said Janabi.

An Internet message attributed to Zarqawi on Wednesday mocked the US strikes.

They are taken "under the pretext that I am in Fallujah. This is not correct, because those fools do not know that I travel in Iraq where I am greeted everywhere by my brothers," he said.

Zarqawi, a fugitive Jordanian Islamist who has a 10-million-dollar US bounty on his head, has been accused by US and Iraqi officials of being behind numerous atrocities in Iraq.

Some believe he may be holed up in Fallujah, a bastion of Sunni Muslim opposition to the US-led occupation.

Zarqawi heads his own militant faction named Tawhid wa al-Jihad (Unification and Holy War) which has claimed responsibility for two huge car bombings in Iraq this month as well as the beheading of a South Korean hostage.

As violence raged across Iraq's Sunni heartland Thursday, fighters in the town of Baquba, northeast of the capital, pledged allegiance to Zarqawi's faction in a pamphlet handed out to residents, threatening them with death if they helped US forces.

WAR.WIRE