Car bombs and a suicide blast hit Shiite districts of Baghdad and south of Iraq's capital on Tuesday, killing at least 50 people on the 10th anniversary of the invasion that ousted Saddam Hussein.
Sunni Islamist insurgents tied to al-Qaeda have stepped up attacks on Shiite targets since the start of the year in a campaign to stoke sectarian tension and undermine Prime Minister Nuri al-Maliki's government.
Tuesday's car bombs exploded near a busy Baghdad market, close to the heavily fortified Green Zone and in other districts across the capital. A suicide bomber driving a truck attacked a police base in a Shiite town just south of the capital, police and hospital sources said.
"I was driving my taxi and suddenly I felt my car rocked. Smoke was all around. I saw two bodies on the ground. People were running and shouting everywhere," said Al Radi, a taxi driver caught in one of the blasts in Baghdad's Sadr City.
Another 160 people were wounded in the attacks, hospital officials said.
No group claimed responsibility for Tuesday's blasts, but Iraq's al-Qaeda wing, Islamic State of Iraq, has vowed to take back ground lost in its long war with American troops. Since the start of the year the group has carried out a string of high-profile attacks.
Gunmen and suicide bombers stormed the well-protected Justice Ministry building in central Baghdad on Thursday, killing 25 people in an attack by the al-Qaeda affiliate.
A decade after U.S. and Western troops swept into Iraq to remove Saddam from power, Iraq still struggles with a stubborn insurgency, sectarian frictions and political instability among its Shiite, Sunni and Kurdish factions.
Syria's civil war is further fanning Iraq's volatility as Islamist insurgents invigorated by the mainly Sunni rebellion against Syrian President Bashar al-Assad try to tap into Sunni Muslim discontent in Iraq.