A string of attacks, including three car bombings in and around Baghdad, killed at least 22 people Tuesday, deepening fears of a surge in violence as sectarian tensions fester in Iraq.
Although there was no immediate claim of responsibility, blame is likely to fall on Sunni insurgents such as al-Qaida's local franchise for Tuesday's bloodshed. The group often uses indiscriminate attacks to sow fear among Iraq's Shiite majority and undermine the government's authority.
It was at least the fourth day this year that insurgents overcame security measures to carry out high-profile attacks claiming at least 20 lives. Over a two-day stretch alone last week, a series of what appeared to be coordinated bombings and other strikes killed nearly 60 people.
The upsurge in violence has coincided with a wave of Sunni-led protests against Prime Minister Nouri al-Maliki's Shiite-led government over what they see as unfair treatment of their sect.
Tuesday's attacks began when a parked car exploded at a security checkpoint in Mahmoudiya, about 30 kilometers (20 miles) south of the Iraqi capital. The blast killed five people, including two soldiers who were manning the checkpoint, and wounded 15, according to police.
A second car bomb, this one detonated by a suicide attacker, went off near a checkpoint in the northern Baghdad suburb of Taji, killing seven people and wounding 26.
Nasseer Rahman, a 35-year-old teacher, said he was sitting in a minibus waiting to pass the checkpoint when the bomb exploded about 120 meters (yards) away.
"The useless checkpoint was the reason for the high casualties because dozens of cars were backed up in long lines before (it) got hit," he said. "As soon as the blast struck, we got off the minibus and ran to the site of the explosion. We saw several cars on fire and pools of blood, and everybody was screaming for help."
Later in the day, another parked car loaded with explosives blew up in the predominantly Shiite neighborhood of Shula in northwestern Baghdad, killing five and wounding 15, police said. The blast left several cars charred and mangled.
Medics at a nearby hospital confirmed the casualties. All officials spoke on condition of anonymity because they were not authorized to speak to the media.
Elsewhere, gunmen killed two government employees and three guards as they were transporting salaries between oil facilities near Beiji, which is home to Iraq's largest oil refinery, about 155 miles (250 kilometers) north of Baghdad.
Police have launched a manhunt for the assailants, who made off with the money, according to Beiji mayor Abid al-Awadh.
Al-Qaida and other insurgent groups occasionally carry out brazen robberies in order to finance further attacks.
Violence has fallen since the peak of the insurgency in Iraq several years ago, but lethal attacks launched primarily by Sunni extremists still occur frequently. The attacks exacerbate Iraq's struggle to maintain stability amid a series of political crises that have wracked the country since the U.S. military withdrawal in December 2011.
The violence comes amid rising ethnic and sectarian tension following the arrest last month of bodyguards assigned to the Sunni Finance Minister Rafia al-Issawi.
The detentions sparked a wave of demonstrations that have swept the Sunni-dominated Anbar province as well as other parts of the country where Iraq's minority Sunnis live.
The protesters, who are rallying against alleged discrimination by the Shiite-led government, demand the release of detainees and want to overturn policies including a tough counterterrorism law that they believe unfairly target their sect.
Al-Maliki earlier this month set up a government committee charged with looking into the protesters' demands. It has focused so far on freeing detainees in an apparent effort to quell the demonstrations.
Deputy Prime Minister Hussain al-Shahristani, one of the prime minister's most trusted political allies, announced Tuesday that more than 1,000 inmates have been set free since the panel began its work.
A delegation of United Nations officials traveled to the Anbar provincial capital of Ramadi on Tuesday to meet with protesters and local officials to better understand their demands, said Eliana Nabaa, a U.N. spokeswoman in Baghdad.
Associated Press writer Sameer N. Yacoub contributed to this report.
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