A bomb killed five Shiite pilgrims in a procession in northeast Iraq on Sunday and blasts in Baghdad killed two more pilgrims as millions of people marched to commemorate the most important Shiite religious observance.
Pilgrims traveling to the southern holy city of Karbala have come under repeated attack during the 10-day religious ceremonies that culminated Sunday with huge processions.
Dozens of pilgrims have been killed and more than 150 wounded during the Ashoura observance by insurgents hoping to intensify sectarian violence that reached a peak in 2006 and 2007, though the pace of violence has dropped sharply since then.
Tight security encircled Karbala, 50 miles (80 kilometers) south of Baghdad, where 25,000 additional security personnel deployed. Snipers watched marchers from rooftops, and bomb detection dogs were used in the search for explosives.
A roadside bomb in the town of Tuz Khormato, 110 miles (180 kilometers) northeast of Baghdad, struck worshippers Sunday morning, killing five and wounding 28, police and medical officials said.
A police official said the Minister for Youth and Sports, Jassim Mohammed Jaafar, was among those in the targeted procession, but was unharmed. One of his bodyguards and a police captain were among the dead.
In western Baghdad, a roadside bomb targeted a minibus carrying pilgrims, killing one and injuring six, another police official said. The casualties were confirmed by a medical official.
Another pilgrim was killed in southern Baghdad late Saturday when a bomb struck a procession, police said. Ten people were injured.
The police and medical officials spoke on condition of anonymity because they were not authorized to release the information to the media.
Sunday's commemorations marked the climax of Ashoura, the yearly mourning period in which Shiite Muslims remember the seventh century death of the Prophet Muhammad's grandson, Imam Hussein, in a battle against overwhelming odds in the central city of Karbala.
To commemorate his death, black-clad pilgrims marched to Karbala in long processions, waving green flags and chanting religious slogans. They marched past crowds of onlookers toward Imam Hussein's shrine, beating themselves around the chest, back and head with fists, chains and swords.
Some wore white robes that were stained with their own blood.
Ashoura processions were banned under former dictator Saddam Hussein's Sunni-dominated regime. Publicly marking the holiday _ despite the threat of attacks _ has become a demonstration of strength for Shiites.
Othman al-Ghanimi, the provincial police chief in charge of Karbala, said he was expecting up to 3 million visitors, including pilgrims from other countries such as Iran, Bahrain and Kuwait.
Iraqi authorities had already thwarted some attempted attacks, and American forces provided explosives-detecting equipment and were offering air support, al-Ghanimi said.
The government increased security after coming under heavy criticism for failing to prevent a series of devastating bombs in the Iraqi capital. It is eager to demonstrate that the withdrawal of American forces will not leave a security vacuum for insurgents to exploit.