BAGHDAD, Aug 13: An Iraqi was killed and four people wounded on Wednesday, the US army said, in the first armed clash between US forces and Shias in Baghdad since the occupation of the country began in April.

A rocket-propelled grenade and gunshots were fired and rocks thrown at US forces who were sent in to deal with a demonstration of about 3,000 people, said Sergeant Danny Martin.

“We returned fire and this resulted in one civilian killed and four wounded,” he said.

The violence flared around midday in the overwhelmingly Shia neighbourhood of Sadr City when a US helicopter tried to remove a black religious flag from a communications tower, a religious leader and witnesses said.

Sheikh Ali al Mutairi, a key aide to firebrand anti-US Shia leader, Moqtada Sadr, said the dead Iraqi was a young boy.

The helicopter hovered over the tower to remove the flag, but a woman 0 crewmember was beaten back by stick-wielding Iraqi men who had climbed the structure to defend their symbol, Mutairi and several others said.

Mutairi said the men then put up four more flags on the tower.

Sergeant Martin said only that the chopper had “apparently flown too close and it apparently blew down the banner”.

Mutairi said US forces responded by shooting in the air and ordering in six Humvees of troops to maintain order. The Iraqis quickly responded with a round of gunfire at US ground troops, and a firefight broke out, he said.

“The shooting lasted about 20 minutes,” Sheikh Mutairi said.

“They pulled out their troops,” he said of the Americans, “and our heroes controlled the situation.”

As crowds swelled toward the area, Iraqi police arrived on the scene in an attempt to quell the unrest but were chased away amid death threats.

A sheikh addressed the crowd with a loudspeaker, ordering them not to use violence until such an order was given by the Hawza, the Shia religious authority in Iraq.

Jalil Mahsen, 39, a labourer, said he helped take several wounded Iraqis to hospital.

“One boy was killed, and there are now 13 wounded in Al Shouader Hospital,” Mahsen said.

Several thousand people were seen demonstrating at the site in the afternoon and chanting anti-American slogans, as five flags including a new black Shia banner were seen fluttering from the tower.

“We are ready to commit suicide attacks against the Americans if we are told to do so,” railed one of the demonstrators, dressed in the white shroud typical of Muslim martyrs.

Muqtada Sadr has spoken out vehemently against the occupation and threatened to mobilize a “Mehdi Army” of volunteer followers to rise up if called upon.

UN OFFICIAL: Leading Iraqis who despised Saddam Hussein will take up arms against US forces if life under occupation does not quickly improve, a senior U.N. official said in outspoken criticism of Washington’s policy in Iraq.