With Shiites marking the final day of the 10-day Ashura ceremony -- Shiite Islam's holiest dates -- dozens came under bomb attacks, mainly in the restive province of Diyala, northeast of Baghdad.

Twenty-three Shiite pilgrims died when a suicide bomber blew himself up in a mosque as they were marking Ashura in Dur Mandali, near the town of Balad Ruz in Diyala, security sources said. A further 57 were wounded.

In another attack, 12 Kurdish Shiites, known as Faylis, were killed when a bomb stashed in a roadside bin exploded as they headed to a local husseiniyah (religious hall) in Khanaqin, also in Diyala near the Iranian border.

Police Colonel Azad Issa said the dead included a woman and a child, and that another 38 people were wounded.

In a third attack, a sniper killed three Shiite volunteers as they served traditional meals to pilgrims near the Diyala provincial capital Baquba.

Shiite Muslims observing Ashura have become a frequent target of Sunni militants.

Later Tuesday, several mortar rounds slammed into the Baghdad Sunni district of Adhamiyah, killing at least 10 people, police said.

Iraq is engulfed in a raging sectarian conflict that has left tens of thousands of people dead in the past year, mostly in Baghdad.

Iraqi and US forces are fine-tuning a new security plan to snuff out the violence.

But the officer tapped to command all US forces in the Middle East said Tuesday that the new plan did not have much time to work.

"I believe the situation in Iraq can be turned around but time is short," Admiral William Fallon told the Senate Armed Services Committee during a confirmation hearing.

"An essential foundation for making progress in this country is for that government to step up and start taking some of these tough decisions," said Fallon.

Hundreds of thousands of Shiite faithful braved insurgent attack to observe Ashura in the central city of Karbala, the site of Islam's definitive Shiite-Sunni divide.

Ashura, which means the tenth in Arabic, falls on the 10th day of the Muslim month of Muharrem.

About 10,000 security personnel guarded pilgrims over the past 10 days to thwart any attacks in Karbala, home to the mausoleum of revered Imam Hussein.

Tuesday marked the climax of Ashura, which commemorates the slaying in Karbala of Hussein by armies of the Sunni caliph Yazid in 680.

A grandson of the Prophet Mohammed, tradition holds that Hussein was decapitated and his body mutilated by Yazid's armies.

To express remorse and guilt for not saving Hussein, hundreds of Shiites were seen flaying themselves with chains or slicing the front of their scalps with swords and knives on Tuesday.

Blood streaming from their heads and backs, men of all ages, dressed in white, walked towards the tomb of Imam Hussein from dawn.

"This is the least we can do for Imam Hussein who sacrificed himself and his family to save the real religion," said Ali Mohammed, 30, who had cut his head with a sword.

"We do not feel pain. In fact we feel we are one with Imam Hussein."

Hundreds of such men, drenched in blood, were seen headed to the tomb.

Shiite pilgrims ended Ashura after midday prayers by completing a final run towards Hussein's mausoleum, a symbolic gesture of Shiites coming to help the imam in his final moments.

Police remained on high alert even as devotees began leaving the city.

Karbala police spokesman Rahim Mussawi said: "We will maintain the security (level) until tomorrow by which time all the pilgrims will have left the city."

Karbala governor Akil al-Khazali said nearly 1.5 million pilgrims visited Imam Hussein's shrine over the 10-day period.

At least eight people died in other attacks Tuesday, while police found eight bodies in Baghdad.