A homicide bomber wearing a belt of explosives blew himself up among Iraqi army volunteers in a town near the Syrian border Friday, killing as many as 25 people. Al Qaeda in Iraq (search) claimed responsibility.

Police and army recruits have been a recurrent target of the Iraqi insurgency; on Friday, the U.S. military said insurgents also killed two Marines. The deaths brought to 11 the number of U.S. fatalities this week — eight of them in combat.

The bomber was "a portly young man carrying a bag in his hand and heading toward us," said Rashid Hamed, who went to volunteer for the army because "I didn't have a job and wanted to make some money."

"I don't remember anything else but waking up in the hospital," Hamed, who was wounded in the attack, said from a hospital bed.

Iraqi police Brig. Gen. Saeed Ahmed (search) and hospital officials said 25 people were killed and 35 wounded in the attack. U.S. authorities put the toll at 10 dead and 21 injured.

An Internet statement posted in the name of Internet Al Qaeda in Iraq said the group led by Jordanian Abu Musab al-Zarqawi (search) carried out the attack in Rabiah, a town 230 miles north of Baghdad.

"One of the lions of a martyrdom brigade of Al Qaeda in Iraq carried out a heroic operation after he wore an explosive belt and entered a center of the idol-worshipping volunteers," said the statement, whose authenticity could not be verified.

The attack followed a grisly pattern repeated dozens of times in Iraq — suicide bombers detonating explosives among recruits or aiming vehicles into crowds of volunteers. Despite measures to boost security, Iraqi authorities seem powerless to stop the attacks.

Security around Iraqi installations has taken on new urgency as the United States and its partners seek to accelerate training of Iraqi forces so they can assume greater security responsibilities and enable American and other foreign troops to begin going home next year.

Since the announcement of the new Iraqi government on April 28, at least 793 Iraqi security forces and at least 1,361 Iraqi civilians have been killed in 477 separate attacks, an Associated Press tally shows. The actual number is likely higher, as many killings go unreported or uncounted. The AP tally is compiled from hospital, police and military officials cited in news stories, as well as accounts from reporters and photographers at the scenes.

Two Marines were killed by insurgent gunfire and rocket-propelled grenades in western Iraq, prompting U.S. jets to drop high-tech bombs that destroyed three buildings used by the guerrillas as firing positions, U.S. officials said. The Marines reported killing nine insurgents, five of them believed to be Syrians, in Thursday's clash about 170 miles west of Baghdad.

An Army soldier died in Baghdad from injuries suffered in a single-vehicle accident, the U.S. command said.

Late Friday, gunmen assassinated a Shiite tribal leader, Faisal Saad Essa, in Baghdad — an attack that could heighten tensions between Shiites and Sunni Arabs.

About 1,000 Sunnis staged a protest earlier in the day near the heavily guarded Green Zone, accusing the Shiite-dominated government's security forces of killing Sunnis under the guise of fighting terrorism. Protesters also demanded that American and other foreign troops leave the country.

Following attacks this month on diplomats in Baghdad, the Philippine Embassy has relocated its employees to Jordan, Philippine Foreign Undersecretary Jose Brillantes said.

"We continue to maintain our diplomatic ties with Iraq," Brillantes said in Manila. "The diplomats in Baghdad are in Amman for security reasons occasioned by the recent kidnappings of diplomats."

Al Qaeda in Iraq claimed responsibility for the kidnap-slaying of three Arab diplomats this month — two from Algeria and one from Egypt — a campaign apparently aimed at isolating Iraq among its Arab and Muslim neighbors.

The U.S. ambassador to Iraq, Zalmay Khalilzad, said Thursday the American military was considering offering protection to foreign diplomats in Baghdad.

Meanwhile, the U.S. military said it captured a cell leader of Al Qaeda in Iraq. Ammar Abu Bara, also known as Amar Hussein Hasan, was arrested Wednesday in Mosul by members of the Army's 1st Brigade, 25th Infantry Division, a U.S. statement said.

Abu Bara was taken into custody during a search operation, the statement said, adding that he replaced Abu Talha, a former terror cell leader for the Mosul area who was arrested last month.

Iraq's chief investigative judge said Saddam Hussein was questioned during a 45-minute hearing Thursday about the crushing of a Shiite uprising in 1991, which erupted after U.S.-led forces drove the Iraqi army out of Kuwait in the Gulf War.

Judge Raid Juhi of the Iraqi Special Tribunal said he expects to conclude the criminal investigation soon into events around the Shiite uprising as well as Saddam's campaign in the 1980s to expel Iraqi Kurds from areas of the north.

Saddam is expected to stand trial in September in the 1982 massacre of Shiites in Dujail north of Baghdad in retaliation for an assassination attempt against him. It would be the first of what are expected to be about a dozen trials involving Saddam and his key lieutenants.