BAGHDAD - A wave of car bomb blasts tore through Shiite areas south of Baghdad on Monday, killing at least 36 and deepening fears that Iraq is rapidly spiraling back out of control.
The attacks capped a week of turmoil that is posing the greatest test of Iraq's stability since U.S. troops left the country in late 2011. At least 218 people have been killed in attacks and battles between gunmen and security forces that began with clashes at a Sunni protest camp in northern Iraq on April 23.
The unrest follows four months of widespread protests among Iraq's Sunni minority, who feel they are discriminated against and are being marginalized by Prime Minister Nouri al-Maliki's Shiite-led government.
Iraqi officials fear that Sunni feelings of disenfranchisement could be exploited by extremist groups such as al-Qaida and militant organizations such as the Naqshabandi Army, which is linked to Saddam Hussein's former regime.
The International Crisis Group recently warned that the standoff between Sunni protesters and the government has begun a dangerous slide toward confrontation.
Monday's deadliest attack struck the southern city of Amarah. Two parked cars loaded with explosives went off simultaneously in the early morning near a gathering of construction workers and a market, killing 18 people and wounding 42, the police said.
That attack was followed by another parked car bombing near a restaurant in the city of Diwaniyah, killing nine people and wounding 23.
Amarah, some 200 miles southeast of Baghdad, and Diwaniyah, 80 miles south of the capital, are heavily Shiite and usually peaceful.
Hours later, another car bomb went off in the Shiite holy city of Karbala, killing three civilians and wounding 14, police said.
And in the otherwise predominantly Sunni town of Mahmoudiya, about 20 miles south of Baghdad, a car bomb ripped through a Shiite neighborhood, killing six people and wounding 14, another police officer said.