An Iraqi man was in critical condition Thursday after he threw an object at US soldiers which they believed to be a grenade, but which witnesses said was simply his shoe.

US Marines shot and wounded the man Wednesday as they conducted a patrol with Iraqi forces in Falluja, a city in western Anbar province, the military said in a statement.

"The Marines who saw the object thrown at the vehicle identified it as a grenade," said Lieutenant Rachel Beatty, a US spokeswoman in western Iraq.

She said the object had not been recovered.

Jassim Mohammed, who witnessed the event, said he saw the man throw his shoe at the US patrol, a rare sight within Falluja since US combat forces were obliged to withdraw from city centres in June under a bilateral security pact.

"Immediately a US soldier in one of the Humvees pointed his gun toward him and shot," he said.

Throwing shoes, an insult in the Middle East, became a symbol of opposition to the US invasion after an Iraqi TV reporter hurled his footwear at then US President George W. Bush in December last year.

Ahmed Mohammed, a doctor at a hospital in Falluja, said the man in Falluja, a 32-year-old mechanic named Ahmed Latif, had been shot in the chest. He was operated Thursday evening and remained in critical condition.

Ahmed Abdul Razzaq, a policeman in Falluja, said the man had been suffering from psychological problems related to fierce battles that US forces have fought in Falluja since the US-led invasion in 2003.

In some of the fiercest fighting of the war, US forces launched two offensives in 2004 in Falluja, then the center of a raging Sunni Arab insurgency, and bombed the city extensively.

Anbar province has been mostly quiet since tribal leaders joined forces with US soldiers in 2006 to drive out al Qaeda.

Uday Latif, the victim's brother, said he believed his brother had thrown a sandal.

"He hates the US military and becomes hysterical whenever he sees US patrols. But he doesn't know how to use a gun and never thought even for a minute to use one," he said, adding that Latif did not suffer psychological problems before 2004.

Uday Latif said his brother had been detained in 2007 by US forces for two weeks.

American forces are due to halt combat operations in August 2010 and withdraw entirely by 2012.

Under a bilateral security pact that took effect last year, US combat troops withdrew from urban bases in June and are only allowed to conduct combat patrols in the cities alongside Iraqi forces.

(Agencies via China Daily?September 18, 2009)