BAGHDAD (AFP) — A US commander warned on Wednesday that despite improving security in Iraq, progress is fragile and "far from irreversible", hours after a massive bomb ripped into a US military convoy in Baghdad. "The enemy still has both the will and the capacity to cause significant loss of life and damage to property," US military spokesman Rear Admiral Gregory Smith told a press conference.
He referred to Wednesday's bombing of the military convoy outside the highly fortified Green Zone in which a US soldier and two civilians were killed, and to an attack by a large group of Al-Qaeda gunmen on the town of Adwaniyah near Baghdad on Monday that was eventually repulsed by US and Iraqi forces.
"There has been significant progress and accomplishments by the combined efforts of the Iraqi and coalition forces in Baghdad and its surrounding areas," Smith said.
"But this progress is fragile and far from irreversible."
The Baghdad blast, which shattered the relative calm that has prevailed in the capital in recent weeks, came as Iraqi officials and politicians were converging on the Green Zone to discuss the reconstruction of war-torn Iraq.
Iraqi security officials said the blast near a police post killed two Iraqi civilians and wounded three.
Smith told AFP that there was "at least one US fatality" in the attack.
A heavily armoured Stryker vehicle of the US military was badly damaged in the blast, which sent a thick plume of smoke into the sky.
An AFP correspondent at the site said a bomb had been planted at the foot of a watchtower at the end of a long row of concrete blast walls protecting a police station, just 100 metres (yards) from a main entrance to the sprawling Green Zone.
The last Stryker in the three-vehicle convoy bore the full brunt of the explosion, which scattered fragments of metal across the street.
Smith told reporters that Monday's day-long clashes in Adwaniyah, in which 15 Al-Qaeda militants were killed, was one of the largest by the local branch of Osama bin Laden's jihadi group in recent months, and "is evidence that Iraq has many enemies."
Meanwhile, police said a suicide bomber detonated his explosives-laden vest at a meeting on Wednesday of Sunni Arab tribal leaders near the town of Iskandiriyah, about 60 kilometres (35 miles) south of Baghdad, killing two people and wounding six.
"A suicide bomber blew himself up in the house of Sheikh Imad al-Gurtani," said police captain Muthana Mohammed of Babylon province.
The Sunni sheikh, leader of the Gurtani tribe which has been spearheading the fight against Al-Qaeda in Babylon province, survived the attack.
In another incident on Wednesday, a US soldier was shot dead during combat operations near the northern city of Mosul, a military statement said.
Another two US soldiers were killed in an explosion while conducting operations in the volatile Diyala province north of Baghdad on Tuesday, a separate statement said, adding that another four troops were wounded.
The latest fatalities brought the military's losses to 857 so far in 2007, the deadliest year for the military since the March 2003 invasion.
The military's overall losses since the invasion have reached 3,862, according to an AFP tally based on Pentagon figures, which also take into account soldiers who die after leaving Iraq for treatment.
The high casualties in 2007 have occurred despite -- or because of -- a "surge" of an extra 28,500 US troops in Iraq since June, a deployment that is seen as a key factor for a drastic dip in sectarian violence across Iraq.
Iraqi government soldiers, meanwhile, shut down the Baghdad headquarters of one of the most powerful Sunni Muslim groups in Iraq on Wednesday, the group said.
Soldiers moved into the Um al-Qura mosque in a Sunni district of western Baghdad where the Committee of Muslim Scholars is based and ordered the occupants out, according to a statement on the group's website.
The raid is seen as yet another sign of the growing battle for influence between the Committee of Muslim Scholars and rival Sunni groups, some of which have joined US forces in the fight against Al-Qaeda.