At least four people have been killed and 28 wounded in bomb attacks against Shia Muslim sites in Baghdad.
The first bomb blew up on Wednesday in the eastern Mashtal quarter of the Iraqi captial as worshippers participated in Ashura rituals.
The blast killed three people and wounded 28, including four women and five children, according to a police officer who did not want to be named.
A further fatality was reported following an explosion at a Shia mosque in Baghdad's central shopping district of Karrada, police said. Four people were also injured in the second attack.
The 10-day Ashura rituals are to mourn the killing of the Prophet Muhammad's grandson, Hussein, by armies of the caliph Yazid in the year 680.
Ashura, which means tenth in Arabic, falls on the tenth day of the Muslim month of Muharram. The festival's climax this year falls on Sunday.
Last year, some 7 million Shia pilgrims, both Iraqi and foreign, travelled to Karbala during Ashura under the protection of 20,000 soldiers and police. Neverthess, some 263 died in the southern cities of Basra and Nasiriya.
In 2004, the first Shia pilgrimage to the Iraqi city of Karbala following the removal of the late Saddam Hussein's government was marred by attacks which also killed and wounded hundreds.
In a third attack in the northern Iraqi city of Mosul, two people were killed and five others were wounded near the Syrian Orthodox church of St Thomas.
The church's priest, Abdul Massih Dalmay, said that Christians in Mosul were being targeted at Christmas approaches. "The security forces, police and army must provide security. The army are responsible for this".
One witness to the attack said the bomb was hidden in a handcart used to carry flour that was then wheeled toward the church.
The attack was the sixth on Christians in Mosul in less than a month.