BAGHDAD — Militants blew up a key bridge Saturday on a highway connecting Iraq's oil-rich north to Baghdad, in what locals warned was part of a campaign to stoke ethnic unrest in the volatile melting pot.
The attack about 110 miles north of Baghdad was viewed as a strike against Iraq's trade routes, which see large convoys traveling north to south. The explosion closed the bridge to big vehicles and triggered warnings from residents that the group Al Qaeda in Iraq has designs on the strategic region around Kirkuk, where ethnic Turkmen live alongside Kurds and Arabs.
"Armed groups are trying to spread sectarianism ... and enmity inside Kirkuk," a city police official said on condition of anonymity.
"Such groups attack the Kurdish community one day; the next day, they attack the Arabs, and the next they target Turkmen, in an attempt to sow the seeds of sedition in Kirkuk's society."
A devastating attack in the Kirkuk region could broaden Iraq's civil war the same way last year's bombing of the Shiite Golden Mosque in Samarra did.
Iraq's Shiite-led Arab government and the semiautonomous northern region of Kurdistan are enmeshed in sensitive negotiations about the fate of the Kirkuk region, which includes the city and the province Al Tamim that surrounds it.
Al Tamim was carved out under the rule of Saddam Hussein to ensure an Arab majority in the oil-rich region. Tens of thousands of Kirkuk's Kurds were expelled as Hussein sought to consolidate his control of the northern oil fields.
The Kurds, who want to annex the Kirkuk region to Kurdistan, are pressing for a referendum this year on the fate of Al Tamim. Although the right to the referendum is guaranteed in the constitution, outsiders fear such a move would spark a greater conflagration, expanding Iraq's civil war to include the Kurds.
Already, Iraq's neighbor Turkey, which is home to a significant Kurdish minority and sees itself as protector of the region's Turkmen population, has warned the Kurds not to annex Kirkuk. In the last week it has amassed troops on the border with Iraq, with the aim of hunting down Kurdish separatists who use the region to stage attacks against Turkish forces.
Iraqi Prime Minister Nouri Maliki visited the Kurdish north Friday and Saturday -- a trip that coincided with the government's push to reach an understanding on Kirkuk, national oil legislation and amendments to the constitution. Alarmed by the Turkish troop movements, Maliki warned Turkey to respect Iraq's borders.
As Iraqi politicians wrangle over the area's fate, bloodshed has risen. In the last week, at least 15 bodies were found around Kirkuk, and a Turkmen politician was killed. Three Iraqi soldiers were kidnapped Saturday southwest of the city.
"This escalation in violence inside Kirkuk has resulted from regional interventions," said Fadhil Qadir, a government employee in the city. "All sides want to politicize the issue of Kirkuk."
Militant groups have become active in the region, particularly with the scattering of Islamist extremists from their former strongholds in Al Anbar province, where Sunni Arab tribes have mostly turned against them, the official said.
Al Qaeda fighters have taken shelter in the Hamrin mountains, which cut across Al Tamim, Salahuddin and Diyala provinces in northern Iraq, the Kirkuk police official said.
In other developments Saturday, Iraqi police reported a U.S. helicopter strike in Baghdad's Shiite neighborhood of Sadr City. Officials believe five British nationals who were kidnapped last week from a Finance Ministry office are being held there.
U.S. helicopters fired on six suspected members of a Shiite militia who were getting ready to fire mortar rounds from the southern edge of the district, a police officer said. Two died and four were injured.
The U.S. military said it had no information about the incident. But U.S. and Iraqi forces have been carrying out raids against Shiite militants linked to radical cleric Muqtada Sadr since the launch of a Baghdad crackdown in mid-February.
A little more than a week ago, Sadr, who had asked his militia to respect the security plan, appeared publicly for the first time since its launch. It is unclear how long he will accept the U.S.-led assaults against his movement.
In the latest tit-for-tat sectarian violence, mortar shells pounded a Sunni neighborhood in Baghdad early Saturday, killing eight people and wounding 25, police said.
The five rounds fell between 1:30 and 2:30 a.m. in the Fadhil slum in central Baghdad, which many Shiites see as a center of the Sunni insurgency. Sunni and Shiite militants often attack each other's neighborhoods with rockets and mortar rounds.
In the western city of Fallouja in Al Anbar, U.S. and Iraqi forces killed seven Al Qaeda members during a raid on a cell manufacturing truck bombs and detained eight suspects, the U.S. military said in a statement.
Iraqi police were backed by U.S. troops and the Anbar Salvation Council, a group of tribes fighting Al Qaeda militants in the province, a senior Iraqi police officer said.
"We were able to kill the wanted criminal Muwaffaq al Jighaifi, who is one of the leaders of Al Qaeda in Fallouja. He was wandering inside the industrial zone using a motorcycle," the officer said.
The U.S. military also announced the death of a soldier injured in a roadside bombing Wednesday in Baghdad. And a U.S. helicopter was forced to make a landing after coming under fire and experiencing mechanical difficulties in Diyala province, military spokesman Army Lt. Col. Christopher Garver said. It was not clear whether the chopper had been hit by the ground fire, he said.
Times staff writers Suhail Ahmad and Raheem Salman in Baghdad and a special correspondent in Kirkuk contributed to this report.