US troops shot dead 13 Iraqis, at least six of them children, during a protest against the presence of the coalition forces, overshadowing the surrender of a key weapons advisor to the toppled president. Witnesses in the town of Fallujah, west of Baghdad, told AFP that US troops had opened fire late Monday on the demonstrators, killing 13 and wounding 45. "The shooting broke out when 500 protestors carrying Iraqi flags approached a school manned by US troops," said Mohammed Hamid, a resident of the town, 50 kilometres (30 miles) west of the capital.

Another witness who asked not to be identified said the US soldiers were "not threatened by the demonstrators."

Of the 13, dead who were swiftly buried Tuesday in accordance with Islamic tradition, six were children aged just seven or eight, the second witness said.

The incident came amid volatile anti-US feeling in the country, nearly three weeks after US tanks rolled into central Baghdad marking the end of Saddam's 24-year grip on power.

US administrators said they were beefing up military patrols in Baghdad to increase security in the chaotic capital, while US President George W. Bush pledged that Iraqis would always have a friend in the American people.

The US campaign to gather intelligence from former regime leaders in the hope of uncovering Saddam's alleged weapons programme progressed with the surrender of another key official.

Amer Mohammad Rashid al-Ubaidi, a former oil minister and weapons adviser to Saddam, gave himself up to US-led coalition forces Monday, US Central Command said.

Rashid was number 47 on the list of most wanted figures of the regime, and the 14th to fall into coalition hands since April 12.

As well as being at the forefront of the development of Iraq's missiles and the systematic campaign to conceal it from the world, Rashid was married to Rihab Taba, known as "Dr Germ", the head of Iraq's secret biological weapons programme, who is still being sought.

The former chairman of Iraq's huge Military Industrialization Corporation closely shadowed the work of UN inspection teams and was considered an expert on Iraq's UN-supervised disarmament.

As a one-time oil minister, he would also know details of Iraq's secret petroleum exports to earn revenue outside the UN-approved oil-for-food programme.

Rashid is the third key weapons specialist to fall into coalition hands, following the head of the Iraqi body that liaised with UN arms inspectors, General Hossam Mohammad Amin, and presidential scientific adviser Amer al-Saadi.

All three men are crucial to finding the elusive "smoking gun" -- evidence to back up Washington's claims that Iraq was developing banned weapons.

The alleged weapons programme was used by the United States to justify going to war in Iraq.

US officials also hope the more people on the wanted list who turn themselves in or are captured, the greater the chances of them finding Saddam himself, whose whereabouts remain a mystery.

In Baghdad, US Major General Glenn Webster told reporters: "In the next two weeks an additional three to four thousand soldiers will move in to protect the city."

The announcement came as Jay Garner, the retired US general in charge of the country, began talks with dozens of Iraqi officials in Baghdad after delegates at a political conference held Monday said security was a top priority.

Speaking at a press conference with Garner before the meeting, Webster said, "We have over 12,000 soldiers serving now but as you know better than me, this is a large and bustling city and 12,000 soldiers can be easily lost in a city this size."

He said US troops would be making patrols of the capital, which continues to be plagued by sporadic violence and looting three weeks after Saddam was toppled, and insisted the US-led coalition was the sole power in Iraq.

Garner stressed that his team would be focussing on security and basic services, and asked for help from the population to weed out those trying to stake a claim to control following the seizure by coalition troops on Sunday of a former exile who proclaimed himself governor of Baghdad.

Garner on Monday hosted a meeting of around 250 Iraqis from across the political spectrum and pledged to bring democracy to the country.

Delegates agreed to hold a conference within a month that would create an Iraqi interim government to take over power when the United States pulls out.

Bush vowed Monday to see Iraq through to democracy and said that the US-led occupation was already improving the lives of Saddam Hussein's former subjects "hour by hour".

"Iraq can be an example of peace and prosperity and freedom to the entire Middle East," he told a cheering crowd in Dearborn, Michigan, home of a large Arab-American community.

"It'll be a hard journey, but every step of the way, Iraq will have a steady friend in the American people," he said, adding that the United States "has no intention of imposing our form of government or our culture" but will ensure that Iraq's new government "will protect the rights of all."

The US military also announced that Washington had moved its combined air command centre from Saudi Arabia to Qatar on Monday.

The announcement came as US Defence Secretary Donald Rumsfeld flew into the former headquarters at Prince Sultan airbase outside Riyadh to meet troops and Saudi leaders.

The visit to a key Gulf ally came after Rumsfeld announced in Qatar on Monday that the United States would reduce its military forces in the Gulf now Iraq no longer posed a threat to the region.

In London, top international experts in Mesopotamian antiquities were to meet to discuss ways to save Iraq's cultural heritage following the looting of the country's museums as the Iraqi war ended.

US forces have came under strong criticism for failing to prevent the looting of treasures of one of the birthplaces of civilisation, notably from the Baghdad archaeological museum.

PHOTO CAPTION

Joyous crowds mock Saddam Hussein's birthday by dressing up a donkey as the former strongman. US troops shot dead 13 Iraqis during a protest to mark Saddam Hussein's birthday in the town of Fallujah, west of Baghdad.(AFP/Ahmad Al-Rubaye)