BAGHDAD — Insurgents launched a fiery raid on a U.S. military outpost north of the Iraqi capital Monday, killing two U.S. troops and injuring 17 in a possible foreshadowing of attacks to come as a neighborhood-based Baghdad security plan takes shape.
Police and witnesses said insurgents thought to be Sunni Arabs used at least one suicide car bomber, mortar shells, rockets and small-arms fire in the attack in the agricultural town of Tarmiya.
Fighting sparked by the rare assault on a U.S. base lasted for hours and ended after U.S. fighter jets and ground reinforcements arrived.
Other attacks around Baghdad and western Iraq killed dozens of Iraqis, most of them Shiite Muslims. The U.S. military also reported the deaths of four more troops since Saturday.
The latest violence coincided with the U.S.-Iraqi security crackdown to bring order to the Baghdad area, in part by establishing small neighborhood bases like the one struck Monday.
The raid, as well as continued assaults on Shiite Muslim civilians, suggests insurgents may be attempting to undermine the security plan by attacking far-flung and lightly fortified outposts.
Although the Tarmiya base is not part of the Baghdad security plan, relatively isolated outposts like it are an integral part of the strategy devised by Army Gen. David H. Petraeus, commander of U.S.-led forces in Iraq.
The plan calls for troops to move into community bases to connect with residents and keep an eye on members of the Iraqi security forces, many of whom are seen as instruments of the country's sectarian war.
Tarmiya, a small Sunni agricultural town of 40,000 people along the west bank of the Tigris River about 25 miles north of Baghdad, has long been an insurgent stronghold. The U.S. base is a former Iraqi police station in the center of town. Iraqi police officials said Tarmiya's police were threatened, kidnapped and killed about two months ago.
Authorities said at least one suicide car bomber either rammed into or drove up beside two trucks carrying fuel into the base about 7:30 a.m., igniting an explosion that sent flames dozens of feet into the air.
"Our windows and doors were broken by the blast," said Mohammed Hiali, 22, who lives near the base. "We went out and we saw fire and thick smoke.... There were repeated explosions."
Insurgents then opened fire with rockets mounted on a truck and from a nearby building, Iraqi police officials said. Mortar shells and small-arms fire added to the confusion as U.S. fighter jets, helicopters and ground forces responded in a battle that raged until noon, witnesses said.
U.S. helicopters landed at least five times to evacuate casualties, Iraqi police officials and witnesses said. At least five Iraqi civilians were injured in the crossfire, including a child who suffered a shrapnel wound to the stomach and was taken to a nearby clinic, said Saadi Mashadani, a grocery store owner in the area.
A group calling itself the Iraqi Islamic State, which has declared a Sunni government in several western and central provinces, claimed responsibility for the attack.
"A brave knight from the Martyrs Regiment and a member of the Iraqi Islamic State set off this morning to infiltrate his booby-trapped car inside Tarmiya police station, which was made into a military position by the crusaders," an Internet posting said.
The U.S. tactic of placing troops in small neighborhood bases in effect reverses the trend since 2004, when American forces redeployed into impenetrable bases on the outskirts of Iraqi cities, lowering their profile on Baghdad streets. The aim was to put Iraqi security forces in charge of the country.
Since that time, Sunni insurgents have become more effective. They are able to conduct sophisticated and well-armed attacks on high-profile targets.
The assault on the Tarmiya base comes at a time when Sunni insurgents have also stepped up their attacks on Shiites in marketplaces and in law enforcement. The tactics may be an attempt to goad Shiite militias back into the fight. At least for now, Shiite militias appear to have lowered their profile to avoid clashes with U.S. troops.
"We are giving orders to state soldiers in Baghdad state to confront the Safawid [Shiite] gangs and protect the Sunnis and their mosques," said a statement posted on the Internet on Feb. 15 that heralded the insurgents' campaign, which it dubbed Operation Dignity.
"We will escalate operations against the crusader occupation army and his tails in all states in order to deteriorate enemy morale," the statement said.
Insurgents launched attacks on Shiite civilians and Iraqi security forces throughout the day in Baghdad, with explosions occurring across the capital. U.S. fighter jets scoured the skies as ground forces continued aggressive raids and patrols that have tripped up Shiite militias and reduced the number of sectarian executions.