A roadside bomb killed six Shiite Muslim pilgrims Friday during a procession, the latest violence targeting the group during observances of a religious holiday, officials said.

The deaths followed heightened tensions in a northern Iraqi town after troops were deployed following a scuffle between Christians and Shiites over holiday decorations.

Observances of the ten-day Shiite festival of Ashoura, which ends on Dec. 27, coincided Friday with Christian celebrations of Christmas.

The government has been trying to assure people it can protect both Shiites and Christians during the two holidays. During Ashoura, hundreds of thousands of pilgrims converge on the holy city of Karbala.

In the days leading up to the event, large processions of men go through the streets of Shiite neighborhoods, beating their chests and using chains to flay their backs in a show of grief over the 7th-century killing of the Prophet Muhammad's grandson, Imam Hussein.

The gatherings, practically banned under Iraqi dictator Saddam Hussein, have often been targeted by insurgents as a way to sow sectarian divide.

The bomb in the capital killed six pilgrims and injured 17, including a local politician, said a policeman in Sadr city in eastern Baghdad. A medic and another policeman confirmed the number of dead. All officials spoke on condition of anonymity because they are not authorized to speak to the media.

In a northern Iraqi town, troops were deployed and a brief curfew was imposed after three guards at a Christian church were injured during a dispute between Shiites and Christians over competing religious decorations.

The confrontation in Bartela, 240 miles (390 kilometers) northwest of Baghdad, comes as many Christians in Iraq tamped down celebrations to avoid offending Shiites, who are making pilgrimages to the southern holy city of Karbala to commemorate the killing of Imam Hussein. His death sealed the split between Shiites and Sunnis.

A police official said Christians in Bartela had pulled down black flags hung to mark Ashoura. The flags were flying near where a church was preparing for Christmas Mass. The police official spoke on condition of anonymity because he was not authorized to talk to the media.

Three church guards were slightly injured in the melee, the police official said. A brief curfew was put in place after the incident.

The office of the provincial governor, Atheel al-Nujaifi, issued a statement saying he and police officials met with leaders of both groups shortly afterward. He blamed "outsiders who wanted to drive a wedge between Christians and Muslims."

Sayyid Harith Al-Odari, an aide to the powerful anti-American cleric Muqtada al-Sadr, said in his Friday sermon, "We offer our thanks and appreciation to our Christian brothers for respecting Ashoura by shortening their celebrations on the occasion of Christ's birth."

The incidents come a day after Shiite pilgrims were targeted in a handful of bombing attacks that left dozens dead. In the worst of those attacks, police on Friday raised the toll to 19 killed and 80 wounded in a double bombing in Hillah, 60 miles (95 kilometers) south of Baghdad.

In the northern city of Mosul, police found three bullet-riddled bodies of staffers working for the provincial census office, said local police and morgue officials.

Northwest of Mosul, near the border with Syria, a car bomb exploded near Kurdish Peshmerga forces, killing one and wounding 10 others, police said.

The officials spoke on condition of anonymity because they were not authorized to speak to the media.