BAGHDAD - Al-Qaida militants commandeered Iraqi army vehicles and then attacked U.S.-backed Sunni fighters in south Baghdad during a fierce gunbattle that left 18 people dead Thursday, police and local Sunnis said.
Later Thursday, mortars or rockets slammed into the U.S.-protected Green Zone - dramatizing warnings by senior American commanders that extremists still pose a threat to Iraq`s fragile security despite a downturn in violence.
The gunbattle began before dawn when al-Qaida militants killed three Iraqi soldiers and seized two Humvees in the rural area of Hawr Rijab on the southern rim of the capital, according to a police report.
Militants then drove the Humvees to the nearby headquarters of the local "awakening council" - Sunnis who have turned against al-Qaida in Iraq. The assailants opened fire on the headquarters with rifles and machine guns from the Humvees, the report said.
U.S. Kiowa Warrior helicopters joined the fight, blasting a van which was transporting a machine gun and mortar tube, the American military said. An F-16 jet dropped a 500-pound bomb and destroyed the vehicle as al-Qaida broke off the attack, the U.S. said, adding that two insurgents were killed.
The dead included eight members of the U.S.-backed group and seven al-Qaida suspects in addition to the three Iraqi soldiers, according to police and local Sunni leaders.
AP Television News footage showed Iraqi police and soldiers forming a protective cordon around wailing women and children as they loaded wooden coffins onto the cars for funeral processions of those killed.
Shortly before sunset, a series of rockets or mortars crashed into the Green Zone, sending up plumes of smoke into the sky as the sounds of the detonations reverberated through the center of the city.
The attack, the biggest against the Green Zone in weeks, occurred as many Americans were marking the Thanksgiving holiday. Loudspeakers in the Green Zone warned people to "duck and cover" and to stay away from windows.
Maj. Brad Leighton, a U.S. spokesman, said there were no fatalities, but some people were wounded. He refused to give numbers or nationalities.
U.S. authorities have attributed some of their success in reducing violence to the role of "awakening councils," which have worked with the Americans to drive al-Qaida from their neighborhoods.
Northeast of the capital, Iraqi security forces killed 19 al-Qaida in Iraq fighters during a gunfight in a mixed Shiite-Sunni village outside Baqouba, police said. They said two civilians were killed and two others were wounded in the crossfire.
In statements posted Thursday on Islamist Web sites, the al-Qaida front group, the Islamic State of Iraq, claimed responsibility for a series of attacks on U.S.-backed awakening groups around the Iraqi capital.
One statement also claimed responsibility for downing a coalition helicopter which crashed Tuesday near Salman Pak. Two soldiers were killed and a dozen were injured.
The statement, translated by the private SITE Intelligence Group, identified the helicopter as American. But British authorities said the aircraft and all those aboard were British. The cause of the crash is under investigation, but U.S. officials said it appeared that ground fire was not responsible.
A spokesman for the Iraqi military, Brig. Gen. Qassim al-Moussawi, downplayed the latest violence, saying U.S. and Iraqi forces were gaining the upper hand and "citizens should be patient for a while to achieve positive results."
American officials say attacks have dropped 55 percent nationwide since June. But American military commanders have repeatedly warned that Iraq is by no means stable, even though the violence is declining.
Nevertheless, the return of relative calm has encouraged thousands of Iraqis to return from Syria, where they fled during the height of the Sunni-Shiite slaughter last year. Many of them expressed confidence that violence would not return.
Others have run out of money because the Syrians will not issue them work permits. Syria also imposed strict visa requirements last month, raising fears among many Iraqis that they would not be allowed to stay.
"Thanks be to God that we arrived here today," Muhanad Ibrahim said as he arrived Thursday in the west Baghdad neighborhood of Mansour. "We have learned that the security situation improved and we hope all Iraqis will get back to Iraq."
The Iraqi embassy in the Syrian capital of Damascus is organizing free trips for Iraqis who want to return home. Iraqi diplomat Adnan al-Shourifi said the first free trip is scheduled Monday, when a convoy of buses and an Iraqi Airways flight will ferry the refugees back to Iraq.
Officials said thousands of Iraqis living in Syria have headed back home in the past weeks.
"We believe that the improvement in the security situation in Iraq is now paying off and we will do our best to receive those who want to join us in building Iraq," government spokesman Ali al-Dabbagh said in an interview from Damascus where he was helping supervise the return program. "It is a sign of hope that life is returning to normal."
Hakam Adnan, a 23-year-old Sunni, returned home after he and his family fled the violence in their western Baghdad neighborhood of Amariyah a year ago.
"I have spent all my savings in Syria. I am glad that I am in Iraq again," he said. "I checked my house and my neighborhood and everything seems fine."
"I called my family, wife and two daughters and told them to come back as soon as possible," he added. "In my country, at least I can maintain my dignity. To live in a foreign country is a very difficult thing."