BAGHDAD - A sharp rise in attacks on Sunni mosques and Shiite places of worship, called husseiniyahs in Iraq is feeding fears that the country could spiral into a new round of sectarian violence similar to the bloodletting that brought Iraq to its knees in 2006 and 2007.
Majority Shiites control the levers of power in post-Saddam Hussein Iraq. Wishing to rebuild the nation rather than revert to open warfare, they have largely restrained their militias over the past five years or so as Sunni extremist groups such as al-Qaida have targeted them with occasional large-scale attacks. That may now have changed.
If it turns out that Iranian-backed Shiite militias are responsible for the recent attacks on Sunnis, it could signal a turn toward cyclical retaliatory violence.
Bombs targeting Sunnis, including two near a mosque and one at a funeral procession, killed 67 people in Iraq on Friday, officials said, after dozens died in two days of attacks on Shiites.
The violence raises the spectre of tit-for-tat killings common during the height of sectarian bloodletting in Iraq that killed tens of thousands of people, and comes at a time of simmering tension between the Sunni minority and Shiite majority.
One bomb exploded as worshippers were leaving Saria mosque in the city of Baquba, north of Baghdad, while a second detonated after people gathered at the scene of the first blast, killing a total of 41 people and wounding 57, police and a doctor said.
"Authorities should stop these daily explosions and car bombs against innocent people," Abbas al-Zaidi, 47, said near the scene of the blasts.
At least 29 Sunni mosques were attacked between mid-April and early May, according to Mahmoud al-Sumaidaie, the deputy head of Iraq's Sunni Endowment, which oversees the sect's holy sites. At least 65 Sunni worshippers were killed, according to a tally compiled by The Associated Press from police reports.
By contrast, two Shiite mosques were hit in bombings that killed one person over the same period, police and hospital officials said.
In all of 2012, there were only 10 recorded attacks on Sunni holy sites, al-Sumaidaie said.
In a sign of increasing fears by the Shiite-led government that the country might be descending into sectarian strife, Prime Minister Nouri al-Maliki warned earlier this month that terrorists and extremist groups are taking advantage of the turmoil by targeting "certain areas and mosques."
"The attempts to stir sectarian strife again by warlords, terrorists, and militia leaders will not succeed and we will confront them with full force," he said, adding that the army and police would boost security around houses of worship.
Even if the will is there, al-Maliki's government is considered too weak to ensure security and control militias and other extremist Shiite groups that are allegedly linked to and partly financed by Iran.
And many contend that al-Maliki's government planted the seeds for more sectarian tension by becoming more aggressive toward Sunnis after the US military withdrawal in December 2011.
For the past five months, Sunnis have been protesting against what they claim is second-class treatment by the government and to demand an end to some laws they believe unfairly target them. Violence has flared on occasion between security forces and protesters.
But the matter came to a head April 23 after government troops moved against a camp of Sunni demonstrators in the town of Hawija, about 240 kilometers (150 miles) north of Baghdad. The clashes there sparked a wave of violence across Iraq that has killed more than 230 people, posing the most serious threat to Iraq's stability since the last American troops left in December 2011.
While the government has made some concessions, such as freeing prisoners and raising the salaries of Sunni anti-Al-Qaeda fighters, underlying issues have not been addressed.
Al-Sumaidaie suggested the spate of recent attacks on Sunni mosques might be aimed at pressuring Sunni protesters to quit their anti-government rallies.
"These attacks aim to terrorize the worshippers and they might be a reaction on some issues such as the protesters," he said.
He also accused Shiite militias of being behind the recent attacks on Sunnis, but refused to specify which groups.
In February, Sunni households in mixed areas of Baghdad began receiving threatening leaflets signed by a militant faction known as the Mukhtar Army. The leaflets called Sunnis the enemy and warned them to leave the neighborhood. Their appearance raised new concerns among many Sunnis in the capital because overt threats like that had largely disappeared as widespread sectarian fighting waned in 2008.
The Mukhtar Army was formed by Wathiq al-Batat, a one-time senior official in Iraq's Hezbollah Brigades, which has no direct link to the better-known Hezbollah in Lebanon. Al-Batat has said the militia's aim is to confront Sunnis who might attempt to topple the Shiite-led government in Baghdad in the same manner that Syrian rebels are trying to overthrow Bashar Assad's Iranian-backed regime in neighboring Syria.
Last week, al-Batat was quoted by Iraqi media issuing new threats against "the centers of terrorism and the people with turbans who are calling for terrorism" — an apparent reference to extremist Sunni clerics.
"We will work to intensify the jihadist operations, by using all means, in order to hunt for these terrorists and strike their economic, social and political interests, and we will not exclude anybody who promotes or calls for terrorism," he said.
Attacks on Sunni mosques have become rare since the peak of the sectarian strife, which was ignited by the bombing of the Shiite al-Askari shrine in the city of Samarra in February 2006. That attack was blamed on al-Qaeda in Iraq and set off retaliatory bloodshed between Sunni and Shiite extremists that left thousands of Iraqis dead and pushed the country to the brink of civil war.
The new wave of unrest rolling across Iraq now is worrying in part because of the country's recent past.
Ryan Crocker, a former U.S. ambassador to Baghdad, warned in an opinion piece in the Washington Post on April 30 that the situation in Iraq has taken "a very dangerous turn" since last month's crackdown in Hawija.
He described the recent violence as reminiscent of the dark days in 2006. Al-Qaida's Iraq arm, he wrote, is regrouping in areas that Iraqi and American forces "cleared at enormous cost," and its ally Jabhat al-Nusra is "attempting to hijack the secular resistance" to Syria's Assad.
"These developments threaten not only to unravel the gains made since 2007, but also to energize the forces of violent extremism in the heart of the Arab world, already burning in Syria," Crocker said.
Interior Ministry spokesman Lt. Col. Saad Maan Ibrahim said the ministry has taken extra precautions to try to secure mosques, including deploying more security forces and undercover policemen.
"The ministry is giving this issue top priority now because we are aware that this tactic has been used before in order to create a sectarian war among the Iraqi people, but they failed," Ibrahim said.
He said that an investigation is underway to determine which groups are behind the mosque attacks, and cautioned against jumping to any hasty conclusions.
"Basically, these attacks bear the hallmarks of al-Qaeda, but we do not rule out the possibility that the militias from the other side might be behind this violence," he said.