Iraqi security and medical sources say at least seven people have been killed by a car bomb in the central province of Salahuddin.
According to the police, at about 1:30 p.m. local time (1030 GMT) on Saturday, a parked car blew up near a restaurant on the outskirts of the city of Balad, killing seven Shia religious tourists, Reuters reported.
Medics said another 25 people were injured in the bombing in Balad, which is situated 80 kilometers (50 miles) north of Baghdad.
The Shia religious tourists were on their way to visit the Al-Askari shrine in the city of Samarra.
The attack occurred on the second day of the Islamic lunar month of Muharram, which is the month that Imam Hussein (PBUH) -- the grandson of Prophet Muhammad (PBUH) -- and his 72 companions were martyred.
The ceremonies commemorating the martyrdom of Imam Hussein (PBUH) will reach the most important point on the Day of Ashura -- the tenth day of Muharram.
Ashura, which falls on November 25 this year, is the anniversary of the day in 680 CE when thousands of forces loyal to the despotic second Umayyad caliph Yazid ibn Muawiyah martyred Imam Hussein (PBUH) and his 72 companions in Karbala, Iraq.
Hundreds of thousands of people flood Karbala for the Ashura religious rituals every year.