A series of bombings struck Baghdad and a livestock market south of the Iraqi capital on Thursday, killing at least 19 and wounding dozens in areas that are home to mostly Muslim Shias — the latest evidence of rising sectarian discord in Iraq.

The deadliest attack occurred around sunset when a pair of bombs exploded nearly simultaneously in Shula in northwestern Baghdad. One was a car bomb that was detonated outside a fast food restaurant and the other blast occurred near a soccer field. The double-bombing killed 15 people and left at least 40 wounded, officials said.

There was no immediate claim of responsibility, but car bombings in Shia areas are a favorite tactic of Sunni extremists such as al-Qaeda's local affiliate. The group, known as the Islamic State of Iraq, considers Shias to be heretics and accuses them of being too closely aligned with neighboring Shia powerhouse Iran.

4 dead, 16 injured in other bombings

Earlier in the day, a car bomb tore through the crowded livestock market in the town of Aziziyah, 55 kilometers southeast of Baghdad. That attack killed three people and wounded eight.

A few hours later, a roadside bomb missed a passing police patrol in western Baghdad but killed a bystander and wounded eight people.

Police and hospital officials provided details of the attacks and the casualty figures. They spoke on condition of anonymity because they were not authorized to talk to the media.

Iraq releases 160 prisoners

A former prisoner hugs his mother after being released from prison in Baghdad, Iraq, Thursday. About 160 prisoners were released Thursday. (Karim Kadim/Associated Press)

Violence in Iraq has fallen since the height of sectarian fighting in 2006 and 2007, but deadly attacks still happen frequently. The latest attacks appear aimed at shaking Iraqis' confidence in the Shia-led government. For the past two months, Sunni Muslims have been protesting what they describe as unfair treatment by the country's Shia-led government. The protests have been largely peaceful.

Meanwhile, Iraqi authorities released a new batch of inmates from a Baghdad prison in a move aiming at calming the Sunni protesters. Deputy Prime Minister Hussain al-Sharistani announced the release of 160 prisoners, including 13 women, during a ceremony at the prison on Thursday.

He said 4,000 prisoners have been released since a government committee was set up earlier this year to consider protesters' demands. The Sunni protests were sparked by the arrest of bodyguards assigned to Finance Minister Rafia al-Issawi, a senior Sunni politician, in December.