Two car bombs tore through parking lots packed with Shiite pilgrims Monday in an Iraqi holy city, pushing the death toll from a week of attacks to more than 170.
The uptick in violence poses a major test for Prime Minister Nouri al-Maliki's new and somewhat shaky coalition government as followers of a powerful Shiite cleric and key ally demanded he fill key security posts.
The blasts struck Karbala as hundreds of thousands of pilgrims were massing for religious rituals marking the end of a 40-day mourning period for the Islamic sect's most beloved saint.
The first attack occurred about 7 a.m. in a parking lot near busloads of pilgrims on the eastern outskirts of Karbala, 55 miles south of Baghdad. Police and hospital officials said six pilgrims were killed and 34 people wounded in that attack.
Another bomb was discovered nearby and dismantled before it could explode, police said.
More than four hours later, a second explosion struck pilgrims on the southern edge of the city, killing at least 20 people, including two soldiers, and wounding 42, the officials said.
There is a vehicle ban in Karbala for the holy period so pilgrims are dropped off at parking lots and walk in.
Monday's attacks followed a triple suicide bombing last week along two highways leading to Karbala that killed 56 and wounded at least 180 -- most of them Shiite pilgrims.
Hundreds of thousands of pilgrims are gathering in Karbala for Monday's ceremonies marking the end of Arbaeen, a 40-day mourning period to observe the seventh-century death of Imam Hussein, the Prophet Muhammad's grandson.
His death in battle near Karbala sealed Islam's historic Sunni-Shiite split -- the ancient divide that provided the backdrop for the sectarian bloodshed in Iraq after the 2003 U.S.-led war.
No group claimed responsibility for Monday's blast, but car bombs and suicide attacks are the trademark of al-Qaida in Iraq and other Sunni religious extremists.
Followers of anti-U.S. Shiite cleric Muqtada al-Sadr, who have been blamed for some of the worst sectarian violence in past years, criticized al-Maliki for not naming new defense, interior and national security ministers.
Al-Maliki formed a new government Dec. 21 after months of political deadlock but has said he needs more time to find security ministers who are apolitical.