BAGHDAD (AP) -- Security forces stormed a Sunni protest camp in northern Iraq on Tuesday, sparking deadly clashes in several towns and sharply intensifying rage at the Shiite-led government. The unrest and a spate of other attacks, mostly targeting Sunni mosques, killed at least 56 people.
The violence could mark an ominous turning point in the four-month Sunni protest movement, which is posing a stubborn challenge to Iraq's stability a decade after the toppling of Saddam Hussein.
There was no immediate claim of responsibility for the attacks on three Sunni mosques, and it was unclear if there was any connection to the storming of the protest camp. Sunni extremists such as al-Qaida have in the past targeted moderate Sunnis. But if Shiite militias were behind the attacks, it would raise fears of a return to the open sectarian fighting of 2006 and 2007 when Iraq was on the brink of civil war.
The raid on the protest camp drew harsh condemnations from Sunni leaders and foreign diplomats, and raised fears that Iraq is being pushed back toward all-out sectarian fighting like that fueling civil war in neighboring Syria.
Prime Minister Nouri al-Maliki swiftly announced the formation of a special ministerial committee to investigate what happened, underscoring worries that anger over the incident could spill out of control.
"What happened today is a total disaster," parliament speaker Osama al-Nujaifi, a Sunni, said at a televised news conference. He appealed for calm and called for those responsible to stand trial.
"If this bloodshed spreads to other provinces, God forbid, there will be a huge fire that we cannot put out," he said.
The security crackdown began at dawn in the former insurgent stronghold of Hawija, about 240 kilometers (150 miles) north of Baghdad. Like many predominantly Sunni communities, the town has seen months of protests accusing the government of neglect and pursuing a sectarian agenda.
The raid occurred four days after a checkpoint jointly run by the police and army near the town came under attack. Militants seized a number of weapons before retreating into the crowd of protesters, according to the Defense Ministry. Authorities had been trying to negotiate with local and tribal officials to hand over those responsible.
Iraq's Defense Ministry said 23 people were killed Tuesday in Hawija, including three soldiers as well as militants who were using the protest grounds as a safe haven. It said members of al-Qaida and Saddam's outlawed Baath Party were among the militants' ranks.
In its account of the raid, the Defense Ministry said it warned demonstrators to leave the protest area Tuesday before moving in.
Amateur video posted on YouTube by protest supporters shows dozens of officers in riot gear and at least four anti-riot water cannon trucks facing off against a group of men. Many of the civilians were carrying swords, and security forces could be heard urging them to retreat as a helicopter hovered overhead.
It was not possible to verify the video's authenticity, but it appeared consistent with Associated Press reporting of the incident.
As Iraqi forces tried to make arrests, they came under heavy fire from several types of weapons and were targeted by snipers, according to the Defense Ministry account. Authorities reported detaining 75 people and seizing multiple machine guns, hand grenades, daggers and swords.
Outrage over the morning raid soon spread through other Sunni parts of the country.
Gunmen tried to storm army posts in the nearby towns of Rashad and Riyadh, leaving 13 of them dead, according to Defense Ministry, police and hospital officials.
Demonstrators also clashed with police in the restive western province of Anbar.
In Fallujah, mosque loudspeakers urged residents to protest in solidarity with Hawija. About 1,000 took to the streets, with some chanting "War, war." Clashes later erupted between gunmen and security forces in the center of the city, leading authorities to announce an overnight curfew.
A policeman near a protest site in Fallujah was killed by sniper fire, according to local officials. In nearby Ramadi, protesters threw stones at a military convoy and set army vehicles ablaze.
Police and health officials separately provided details of several other attacks, including the three at Sunni mosques.
In Baghdad's Dora neighborhood early Tuesday, two bombs went off near a mosque, killing seven worshippers and wounding 17.
Then in the evening, a bomb exploded as people were leaving a mosque in the town of Muqdadiya, about 90 kilometers (60 miles) north of Baghdad, killing eight worshippers and wounding 20 others. And gunmen opened fire on worshippers leaving a mosque in northeastern Baghdad, killing three worshippers and wounding nine.