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Iraqi security forces locked down areas around the infamous Abu Ghraib prison and another high-security detention facility on Baghdad's outskirts Monday to hunt for escaped inmates and militants after daring insurgent assaults set hundreds of detainees free.

The carefully orchestrated late-night attacks killed dozens Sunday, including at least 25 members of the Iraqi security forces. Insurgents fired dozens of mortar shells and detonated suicide and car bombs, drawing Iraqi forces into firefights that lasted more than an hour.

Attacks elsewhere claimed at least 18 more lives on Monday, many of them soldiers, highlighting the rapidly deteriorating security conditions across Iraq.

The prisons in Abu Ghraib and Taji house thousands of prisoners, including convicted al Qaeda militants. Exactly one year ago, al Qaeda's Iraq arm launched a campaign called "Breaking the Walls" that made freeing its imprisoned members a top priority.

A surge of violence across Iraq has killed more than 3,000 people since the start of April, and the assaults on the prisons laid bare the degree to which security has eroded in the country in recent months. The spike in bloodshed is intensifying fears of a return to the widespread sectarian killing that pushed the country to the brink of civil war after the 2003 U.S.-led invasion.

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    Several officials, including lawmakers on parliament's security and defense committee, said more than 500 inmates managed to escape from Abu Ghraib. There were no immediate reports of escapes from Taji.

    Authorities imposed curfews around both prisons as manhunts got under way. Guards at Taji appeared visibly on edge Monday, with rifles at the ready and wary police warning motorists not to idle even briefly nearby.

    "This big security failure shows that the top security commanders have failed to sort out any solutions for the ongoing security deterioration," said Shawan Mohammed Taha, one of the lawmakers who confirmed the escapes. "The terrorists, not the security forces, are now taking the initiative."

    Another lawmaker, Hakim al-Zamili, said many of the escaped inmates had been captured or killed by Monday afternoon. He said authorities believe the attack on Taji was a distraction, and that Abu Ghraib was the main target.

    So many prisoners were able to get away from Abu Ghraib because they were in the prison yard for the communal iftar meal that ends the daylong fast during the Islamic holy month of Ramadan, said a senior intelligence official and two other government officials.

    They also confirmed the number of escaped inmates and said an investigation has now been launched into who ordered the open-air Ramadan feast. They spoke on condition of anonymity because they were not authorized to discuss the investigation.

    A preliminary investigation suggests the insurgents had inside help, said the Interior Ministry.

    As battles at the prisons raged between gunmen and guards, rioting inmates set fire to blankets and furniture, police said. Army helicopters were called in to help thwart the attacks, according to the Interior Ministry. It confirmed the escape of "several prisoners," without providing details.

    Police reported 15 soldiers and 13 others wounded in the Taji attack, along with six militants. Ten policemen were killed and 19 others were wounded in Abu Ghraib, and also four militants, according to police and hospital officials, who all spoke on condition of anonymity because they weren't authorized to release the information.

    A total of 21 prisoners were killed and another 25 wounded during the attacks, according to Justice Ministry spokesman Wissam al-Firaiji.

    The U.S. military previously operated the lock-ups in Taji and Abu Ghraib but handed control of both facilities back to Iraqi authorities before the last American troops departed in December 2011.

    Abuse of prisoners at the hands of American guards inside Abu Ghraib sparked outrage around the world and helped fuel anti-American sentiment in Iraq.

    Jailbreaks are relatively common in Iraq.

    A dozen prisoners, including al Qaeda-linked death row inmates, escaped from the Taji prison in January after seizing guards' weapons. And in September, scores more inmates got away following clashes at a prison in Saddam Hussein's hometown of Tikrit that left 12 people dead.

    Still, the scale of this week's attacks was significant and "appears to have been an operation long in the planning" by al Qaeda, said Charles Lister, an analyst at IHS Jane's Terrorism and Insurgency Center.

    Al Qaeda's Iraq arm, now known as the Islamic State of Iraq and the Levant, has been positioning itself as a champion of minority Sunnis disillusioned with the Shiite-led government. It is also pushing to make itself a major player among the Sunni rebels fighting to topple the government in neighboring Syria.

    "Releasing ordinary prisoners will help gain the group the image of a Sunni armed force representing Sunnis in a Shiite-governed state. Releasing militants will clearly provide a huge boost in morale," particularly if they include senior commanders, Lister said. "Depending on actual numbers, this could well boost (the group's) operations in Iraq but also feasibly in Syria."

    In a separate incident early on Monday, a suicide bomber rammed his explosives-laden car into an army convoy in northern Iraq, killing at least 13 people, ten of them soldiers, according to police and hospital officials. They said 16 people were wounded.

    Mosul, 220 miles northwest of Baghdad, is one of Iraq's major flashpoints and a stronghold for insurgents, including al Qaeda. Officials who gave the details of the attacks there also spoke on condition of anonymity because they weren't authorized to speak publicly.

    In another attack, provincial council member Abdullah Sami al-Assai was killed along with his two bodyguards in a drive-by-shooting near the center of the ethnically disputed northern city of Kirkuk, according to Kirkuk deputy governor Rakan al-Jubouri and police.

    Two other people were killed when a bomb exploded in a commercial street in Madain, 14 miles southeast of Baghdad, shortly before sunset, according to authorities.

    Ramadan this year is shaping up to be the bloodiest since 2007, with more than 350 Iraqis killed since the holy month started on July 10.