BAGHDAD -- A suicide bomber driving a vehicle packed with explosives blew himself up outside the offices of a major Kurdish party in northern Iraq early Wednesday, the deadliest in a wave of morning attacks that killed at least 31 people across the country.
The violence comes amid rising tensions among Iraq's ethnic and sectarian groups that threaten to plunge the country back into chaos nearly a decade after the U.S.-led invasion. While there was no immediate claim of responsibility, car bombs and coordinated attacks are favorite tactics of Sunni insurgents, such as al-Qaida's Iraq branch. They seek to exacerbate divisions within Iraq in an effort to undermine the Shiite-led government.
The car bomb outside the offices of the Kurdistan Democratic Party in downtown Kirkuk caused widespread damage, mangling cars and tearing apart storefronts on a busy commercial street. The KDP is led by Massoud Barzani, the president of Iraq's largely autonomous Kurdish region, who has frequently sparred with Iraq's central government in Baghdad.
Sadeeq Omar Rasoul, the head of Kirkuk health directorate, said 17 people were killed in the blast. Another car bomb that exploded nearby killed another two people. At least 190 were wounded in the two attacks, he said.
Kirkuk, 290 kilometers (180 miles) north of Baghdad, is home to a mix of Arabs, Kurds and Turkomen, who all have competing claims to the oil-rich area. The Kurds want to incorporate it into their self-ruled region in Iraq's north, a proposition strongly opposed by Arabs and Turkomen.
The city is at the heart of a snaking swath of territory disputed between the Kurds, who have their own armed fighting force, and Iraq's central government.
A shootout in Tuz Khormato, another contested town along the disputed area, prompted both sides to rush troops and heavy weapons to the area in November.
On Wednesday, another car bomb struck the local headquarters for Kurdish security forces in Tuz Khormato, killing five and wounding 36, according to Raed Ibrahim, the head of the provincial health directorate. The town is about 210 kilometers (130 miles) north of Baghdad.
The attacks came as hundreds of mourners gathered in the western city of Fallujah to bury a prominent Sunni lawmaker assassinated by a suicide bomber on Tuesday.
The politician, Ifan Saadoun al-Issawi, was part of the Sunni-backed Iraqiya bloc, which holds some posts in Iraq's loose power-sharing government, but at the same time is the main force in opposition to Prime Minister Nouri al-Maliki's administration. He was also a founder of the local branch of the Sahwa, a group of Sunni Arabs who joined forces with the U.S. military to fight al-Qaida at the height of Iraq's insurgency.
Fallujah and the nearby city of Ramadi have been the scene of more than three weeks of demonstrations against the government.
A planted bomb went off as mourners gathered to mark al-Issawi's death, wounding three of them, authorities said.
A host of smaller attacks hit other parts of the country as well.
In Baghdad, gunmen killed three policemen as they were sitting in their patrol car, a roadside bomb killed two other officers on a highway in the capital and gunmen shot dead an army officer at a checkpoint, officials said.
One policeman was killed and four others wounded when a roadside bomb struck their car in Hawija, 240 kilometers (160 miles) north of Baghdad, according to authorities.
The officials providing details of the attacks outside the disputed areas spoke on condition of anonymity because they weren't authorized to release the information to reporters.
Violence has fallen since the peak of insurgency several years ago, but lethal attacks still occur frequently.
Wednesday's violence was the deadliest in the country since Nov. 29, when attacks mainly targeting Shiite pilgrims in southern Iraq killed at least 43 people.