Coordinated car bomb attacks in the Iraqi holy city of Karbala and twin bomb blasts in Pakistan's largest city, Karachi — all targeting Shiite pilgrims — killed at least 65 people and wounded more than 250 on Friday.
A car bomb ripped through a crowd of Shiite pilgrims outside Karbala, sending many fleeing into the path of a suicide attacker who detonated a second bomb in coordinated blasts that killed at least 40 people and wounded 150.
The pilgrims were marching to the burial place of Imam Hussein, grandson of Islam's prophet Mohammed and Shiite Islam's most revered martyr, to mark Arbaeen, the last day of a 40-day period of mourning that began in late December.
There was no immediate claim of responsibility for Friday's blasts, but Prime Minister Nouri al-Maliki blamed al-Qaida and loyalists of Saddam Hussein, saying in a statement the two groups failed to ignite sectarian strife and destabilize the country with the attacks on pilgrims.
Two other major attacks this week targeted Shiite pilgrims, killing at least 77 people.
Also Friday, a roadside bomb struck a bus carrying pilgrims through Baghdad, killing two and wounding 13, police and hospital officials said.
In Karachi, militants bombed a bus carrying Shiite worshipers and, two hours later, attacked a hospital treating the victims, killing 25 people and wounding 100.
Prime Minister Yousuf Raza Gilani appealed for calm in Karachi, which is Pakistan's commercial heart and has a history of religious violence between Shiite and Sunni Muslims. In late December, extremists in the city detonated a bomb that killed 44 Shiites attending a procession to mark Ashura, the anniversary of the death of Imam Hussein, sparking the city's worst riots in recent years.
No group claimed responsibility, but Pakistan is home to many al-Qaida-linked Sunni extremist groups with a history of attacking Shiites.