Baghdad - A "war on mosques" - deadly attacks by militants on Sunni mosques and Shi'ite places of worship called husseiniyahs - using weapons ranging from bombs to mortar rounds is raging in Iraq.
Dozens of attacks this year have stirred already-simmering sectarian tensions between Iraq's Sunni minority and Shi'ite majority, and led some would-be worshippers to stay away.
"There is an increase in the frequency of reciprocal attacks targeting Sunni and Shi'ite mosques," political analyst Ihsan al-Shammari said.
"It is a war on mosques."
Iraqis have lived with near-daily violence since the 2003 US-led invasion of the country that toppled dictator Saddam Hussein, and militants still attack both security forces and civilians almost each day.
Now, they have set their sights on mosques as well.
45 mosques targeted this year
In one of the deadliest attacks, two bombs exploded near the Sunni Saria mosque in Baquba, north of Baghdad, after prayers on Friday.
One device blew up as worshippers were leaving, and the second went off after people gathered at the scene of the first blast, killing a total of 41 people.
The attacks came after a suicide bomber detonated an explosives-rigged belt on Thursday at the entrance to Al-Zahraa husseiniyah, where family members were receiving condolences for victims of violence the day before.
That bombing killed 12 people. And there have been many more such attacks.
Sheikh Sami al-Massudi, deputy head of the Shi'ite endowment which manages Shi'ite religious sites in Iraq, said that more than 45 mosques and husseiniyahs belonging to the endowment have been targeted this year.
And an official from the Sunni endowment said that more than 10 mosques had come under attack in the past month alone.
"We are threatened, to the point that we did not go to work last Monday after we received threats," the official said.
It is unclear which group or groups are behind the violence.
Sunni militants are almost certainly behind attacks on Shi'ite places of worship. But Sunni mosques may be attacked by either Shi'ite militants, or by Sunnis punishing worshippers for not adhering to a hardline interpretation of Islam.
Whoever is behind the bombings, they have certainly had an effect on attendance.
"I stopped going to pray after the closure of the mosque near our house because of the attacks," said Ihsan Ahmed, a 25-year-old Sunni.
A bomb killed the muezzin, who calls worshippers to prayer, at the mosque about two weeks ago, Ahmed said.
"All this happened in front of my eyes. How can I go again? Even my wife and my children prevent me from going," he said.
Ali, a 29-year-old Shi'ite, said that some people have become afraid to go to husseiniyahs for prayers as well.
"People have become reluctant to go to husseiniyahs, but I did not stop," Ali said.
On Sunday, Prime Minister Nouri al-Maliki called for joint Shi'ite-Sunni prayers on Fridays in a major Baghdad mosque.
"Those who target mosques are enemies of Sunnis and Shi'ites alike, and are planning to ignite [sectarian] strife," he said in a statement.
Tensions are festering between the government of Maliki, a Shi'ite, and Sunnis who accuse authorities of marginalising and targeting their community through wrongful detentions and accusations of involvement in terrorism.
260 killed this month
Protests broke out in Sunni areas of Iraq almost five months ago.
While the government has made some concessions, freeing prisoners and raising the salaries of Sunni anti-al-Qaeda fighters, the underlying issues have not been addressed.
On 23 April, security forces moved against protesters near the town of Hawijah in Kirkuk province, sparking clashes that killed 53 people.
Dozens more died in subsequent unrest that included revenge attacks on security forces, raising fears of a return to the all-out sectarian conflict that ravaged the country between 2006 and 2008.
The violence has not let up in May, with more than 260 people killed in attacks so far this month.
United Nations envoy Martin Kobler has appealed for Iraqi leaders to bring a halt to the violence, including the attacks on mosques.
"It is the responsibility of all leaders to stop the bloodshed," Kobler said. "Small children are burned alive in cars. Worshippers are cut down outside their own mosques. This is beyond unacceptable."