By Tim Cocks
BAGHDAD (Reuters) - U.S. forces came under an Iraqi mandate on Thursday for the first time since the 2003 invasion of Iraq, and handed control of the Green Zone in central Baghdad to Iraqi troops in a symbol of the dramatic change.
The U.S. force in Iraq, now more than 140,000 strong, had operated since 2003 under a U.N. Security Council resolution.
But at midnight on New Year's Eve, the U.N. mandate expired and the troops were placed under a new mandate granted by the Iraqi government in a bilateral deal reached with Washington.
The pact gives U.S. troops three years to leave Iraq, revokes their power to detain Iraqis without a warrant, and subjects contractors and U.S. troops in some cases to Iraqi law.
An Iraqi band played bagpipes at a small ceremony on a street surrounded by concrete blast walls and razor wire in the Green Zone, a fortified swathe of central Baghdad off limits to most Iraqis, who widely view it as a symbol of occupation.
"I convey the armed forces' vow ... that they are able to take full responsibility, so that Iraq again will be secured by the hands of its own citizens," Defence Minister Abdel Qader Jassim told dignitaries assembled under a marquee festooned with tinsel and balloons.
Col. Steven Ferrari, 50th Infantry Brigade Combat Team commander responsible for U.S. troops in the area, called it "a new day for sovereign Iraq.
"As a sovereign nation, Iraq assumes the full range of security responsibilities for this historically ancient land."
On Wednesday, U.S. officials finished vacating the marble Saddam-era Green Zone palace from which they ruled Iraq directly for more than a year after the invasion. Over recent weeks they moved into a newly built embassy compound, the world's biggest.
U.S. troops across Iraq remain under U.S. command but their operations must now be authorised by a joint committee and they can detain Iraqis only with a warrant from an Iraqi judge. They are to leave the streets of Iraqi towns and cities by mid-2009 and withdraw from the country by the end of 2011.
Some 15,000 prisoners held at U.S. military detention camps must now be charged with crimes under Iraqi law or freed.
The new, tough terms of the U.S. presence were secured by an increasingly confident Prime Minister Nuri al-Maliki, emboldened by a maturing government, military victories against Shi'ite militias and progress against al Qaeda militants.
Iraqi officials say they will be cautious in opening up the Green Zone -- which contains government buildings as well as Western diplomats. Private mini-armies of Peruvian and Ugandan security contractors who patrol the zone will remain in place until September. U.S. forces will be present in a support role.
In a separate ceremony in the southern city of Basra, British troops turned over control of the airport to Iraqis.
Britain, the main U.S. ally in Iraq, has signed its own pact requiring its 4,100 troops to leave in seven months, ending Britain's biggest military campaign since World War Two.
"Handing over the airport means the security situation is good and improving quickly. Basra airport is ready to receive bigger planes and flights," the British commander, Major-General Andy Salmon, said.
Iraqi forces take over a dramatically different Iraq from the one ravaged by sectarian violence in 2006 and 2007.
Attacks have dropped sharply, thanks partly to an increase of troops ordered by President George W. Bush in 2007 and also to newfound cooperation from Sunni Arab tribal leaders.
Militants continue to strike with bomb attacks that often target civilians. According to Health Ministry figures, 5,379 civilians were killed during the year, less than a third of the 16,232 killed in 2007 but still an average of nearly 15 a day.
In December, 238 civilians were killed. During the height of fighting two years ago, monthly tolls often ran close to 2,000.
This month will see provincial elections that U.S. and Iraqi officials bill as a milestone towards democracy. But Iraq remains deeply scarred. Baghdad neighbourhoods are divided by concrete walls. Millions who fled have yet to return home.
Majid Mola, an engineer, dismissed as meaningless the handover billed by Maliki's government as a major victory.
"Where are the government services? Where is the electricity? People want practical things," he said.
(Additional reporting by Khalid al-Ansary; Editing by Charles Dick)