BAGHDAD — A suicide bomber blew himself up inside Baghdad’s largest Sunni mosque Sunday night, killing 29 people during prayers, a shocking strike on a place of worship similar to the one that brought Iraq to the brink of civil war five years ago.

Iraqi security officials said parliament lawmaker Khalid al-Fahdawi, a Sunni, was among the dead in the 9:40 p.m attack.

Maj. Gen. Qassim al-Moussawi, a spokesman for Baghdad’s military operations command, confirmed the bombing happened inside the Um al-Qura mosque during prayers in the western Baghdad neighborhood of al-Jamiaah. The blue-domed building is the largest Sunni mosque in Baghdad.

Two security officials and medics at two Baghdad hospitals put the casualty toll at 29 dead and 38 wounded. All spoke on condition of anonymity because they were not authorized to release the information.

No group immediately claimed responsibility for Sunday’s bombing, but suicide attacks generally are a hallmark of al-Qaida, which is dominated by Sunnis. Intelligence officials have speculated that al-Qaida will do almost anything to re-ignite sectarian violence, but the group recently had focused on attacking Iraqi security forces and the government to prove how unstable Iraq remains.

“I heard something like a very severe wind storm, with smoke and darkness, and shots by the guards,” said a shaken Mohammad Mustafa, who was inside the mosque and was hit in the hand by shrapnel.

“How could this occur?” he said. “Is al-Qaida able to carry out their acts against worshippers? How did this breach happen?”

That the bomber detonated his explosives vest inside the mosque is particularly alarming, as it is reminiscent of a 2006 attack on a Shiite shrine in the Sunni city of Samarra that fueled widespread sectarian violence and nearly ignited a nationwide civil war. In that strike, Sunni militants planted bombs around the Samarra shrine, destroying its signature gold dome and badly damaging the rest of the structure.

The attack hit Sunnis who were praying in a special service during the holy Muslim month of Ramadan, which ends Tuesday.

It demonstrates anew that security measures to protect Iraqis as U.S. forces prepare to leave remain riddled with gaps, and shows the extent to which militants want to extend violence even as the eight-year- U.S. presence winds down.

The strike happened hours after the U.N.’s outgoing top diplomat in Iraq said the government in Baghdad must determine whether its security forces are strong enough to thwart violence before requiring U.S. troops to leave at the end of the year.

In his last interview after two years in Baghdad, U.N. envoy Ad Melkert said Iraqi security forces have made “clear improvements” but declined to say if he thinks they are ready to protect the country without help from the American military.

“It’s up to the government, really, to assess if it is enough to deal with the risks that are still around,” Melkert said to The Associated Press.

“Obviously, security remains a very important issue.”

The U.S. and Iraqi governments are negotiating how many American troops might stay, and what role they would play, in a mission that has already lasted more than eight years. A 2008 security agreement between Baghdad and Washington requires all U.S. troops to be out of Iraq by Dec. 31, but the country’s shaky security situation and vulnerability to Iranian influence has prompted politicians on both sides to buck widespread public disapproval and reconsider the deadline.

A decision on whether U.S. troops will remain is not expected for several weeks at least, and the American military is already starting to pack up to leave. About 46,000 U.S. troops currently are in Iraq. The White House has offered to keep up to 10,000 there.

Violence has dropped dramatically across Iraq from just a few years ago, but deadly attacks still happen nearly every day.

Printed on Monday, August 29, 2011 as: Suicide bomb kills 29 in Iraqi mosque.