In an incident that will further fuel popular hostility to the American occupation of Iraq, US troops killed at least two men in Baghdad on Wednesday when they opened fire on a protest outside the US administration’s headquarters.

About 500 demonstrators confronted a line of 40 troops armed with bayonet-mounted assault rifles standing behind razor-edged concertina wire. Chanting slogans and waving banners, they were mostly ex-soldiers opposing the American chief administrator Paul Bremer’s disbandment of the 400,000-member Iraqi regular army, leaving them and their families destitute. They were also demanding payment of salaries still unpaid more than three weeks after Bremer’s May 23 decision.

Angry demonstrations have taken place virtually every day outside the arched gate leading to the compound of Saddam’s former Republican Palace, now housing US offices. On May 26, up to 5,000 former military personnel staged a demonstration. But observers said the protests, which have also seen civil servants demanding new jobs or back wages, have been largely peaceful.

Nevertheless, the US Central Command immediately defended the killings, accusing protesters of tossing rocks at a military convoy as it tried to pass through. “One demonstrator pulled out a weapon and began shooting,” said a statement from Central Command hours after the incident. “US forces responded, killing two of the demonstrators.”

This account is at odds with eyewitness reports. According to Associated Press, Samir Mizban, one of its photographers, said a civilian driver fired a pistol into the air after crowds began smashing his car. Mizban said the protesters were stoning every vehicle within range.

“It was a new car. The demonstrators broke the windscreen with wooden sticks. The driver tried to escape, so he fired in the air with his pistol,” Mizban said. After the driver fired his gun, the enraged crowd threw rocks at the American soldiers blocking the palace gate and at journalists, who fled. US troops then opened fire, Mizban said.

The killings are indicative of US officials and soldiers responding indiscriminately with a mixture of fear and brute repression against an increasingly outraged and vocal population. Reporting for the Independent, Patrick Cockburn commented: “The shooting of the demonstrators appears to be part of a pattern under which the US army responds to any dissent.”

Many demonstrators who spoke to reporters were old and only nominally part of Saddam Hussein’s armed forces, but were refused retirement by the previous regime. Others said that during the war, US planes had dropped leaflets promising them fair treatment if they did not fight. They bitterly condemned the American occupation.

Ryad Abdul Wahab, whose right arm is now only a stump, said: “I was wounded ... in the fighting at the airport during the war and now I can get no pension. How can I survive?” Others said they had nothing to live on and were being punished, though they had refused to fight for Saddam Hussein.

“We did not fight for Saddam but we will fight for our children,” said Major Kassim Ali, formerly an artillery officer. He said they wanted back pay, pensions and the re-establishment of the army. He added: “If a country has no army it cannot be independent.”

The shootings seem certain to provoke reprisals. Some demonstrators threatened suicide attacks on American soldiers. A former sergeant predicted violence against Americans would increase. “We have weapons including RPGs (rocket propelled grenades),” he said. “We may use them if our demands are not met.”

Just hours after the killings, gunmen in a car fatally shot a US soldier and wounded another as they guarded a propane gas distribution point, amid signs of growing resistance to the US occupation. It was the second American fatality in Baghdad and the fourth across Iraq this week, bringing to 188 the number of soldiers killed in Iraq since the invasion began on March 20.

The mood in the capital has become increasingly hostile this week as US troops intensified sweeps and searches across the city and the country in the name of hunting down weapons and Ba’ath Party supporters. Before dawn on Wednesday, troops sealed several streets of the Karrada neighborhood and ordered residents from their beds to stand in the street as they searched their homes. One man was taken away with his hands bound behind his back.

The military said about 400 people had been arrested since the latest operation, dubbed Desert Scorpion, began on Sunday. There were reports of prisoners being taken away blindfolded. “They (the Americans) are worse than Saddam,” Khalid Ibrahim, a 50-year-old driver, told the Guardian. He was among two dozen people arrested and interrogated outside a mosque in Baghdad last weekend and released after five hours.

Apart from the increasingly heavy-handed methods of repression, the resentment is also being fuelled by the American destruction of Iraq’s social and economic infrastructure. Over the past 10 days, electricity shortages have meant that during the extreme heat of the Iraqi summer most people have no air conditioning or refrigerators to prevent food rotting.

“Excessive force” used in Fallujah

The US Central Command version of Wednesday’s events is another crude attempt to cover up the killing of demonstrators. Just a day earlier, Human Rights Watch released a report saying troops used excessive force in Fallujah when they shot and killed 20 protesters and wounded nearly 90 on April 28 and April 30.

Since the killings, Fallujah, a city of 300,000 about 60 kilometres west of Baghdad, has become a centre of resistance to US rule. Ambushes on American forces by unknown gunmen have left four American soldiers dead and 21 wounded.

Human Rights Watch said its two investigators, who visited and photographed the scene of the shootings and interviewed witnesses and participants on both sides, found no evidence to support American assertions that troops fired on gunmen in the crowd.

The researchers saw few bullet holes that would suggest that the crowd of protesters fired on the soldiers using a school as a base. But they discovered more than 100 bullet holes on seven buildings across the street. The evidence, the report said, was inconsistent with American statements that the soldiers responded with “precision fire” when they were allegedly attacked.

“The buildings across the street facing the school had extensive evidence of multi-calibre bullet impacts that were wider and more sustained than would have been caused by the 'precision fire’ with which the soldiers maintain they responded, leading to the civilian casualties that day,” the report stated. “Witness testimony and ballistics evidence suggest that US troops responded with excessive force to a perceived threat.”

The report produced directly conflicting accounts of the first shooting on April 28. Soldiers were quoted saying they fired for 30 seconds after seven men fired at them, five from the crowd and two on roofs across the street. A statement issued by US Central Command the day after that shooting said “approximately 25 armed civilians” fired on the soldiers.

But witnesses told Human Rights Watch that the soldiers fired for 10 minutes and shot those who came to the aid of wounded people. Protesters also said that American soldiers prevented ambulances that were clearly marked from entering the area. Seventeen people were killed and more than 70 were wounded in the incident, Iraqi witnesses said.

In a second shooting on April 30, soldiers from another unit in the 82nd Airborne said they returned fire after being shot at while moving through Fallujah in a convoy. Protesters said they threw rocks at the Americans but never fired. According to them, three Iraqis were killed and at least 16 were wounded.

Human Rights Watch called for a full, independent and impartial investigation, with access to classified evidence, such as communications between US commanders, to determine whether members of the US 82nd Airborne Division or higher US authorities violated international humanitarian law.

“Regardless of the possible responsibility of the individuals involved in the shooting that led to the killing of up to twenty and wounding of scores of others, one conclusion is inescapable. US military and political authorities who placed combat-ready soldiers in the highly volatile environment of al-Fallujah without adequate law enforcement training, translators, and crowd control devices followed a recipe for disaster...

“Under international humanitarian law, the United States, as the occupying power in Iraq, has the obligation to restore and ensure public order and safety, in conformity with international human rights standards.”

The report confirms that, at the very least, the Bush administration and the Pentagon have ordered war-weary, tense and heavily-armed troops to suppress all signs of the mounting opposition to American rule.

While a full investigation is absolutely necessary, it is clear that such shootings are not an aberration. They result directly from the colonial-style US takeover of Iraq, which is increasingly taking the form of a war against the entire population.