A series of bombings struck Baghdad and towns south of the Iraqi capital today, killing at least 22 and wounding dozens in areas that are home to mostly Muslim Shiites, the latest evidence of rising sectarian discord in Iraq.

The attackers struck a day before tens of thousands of Sunni Muslims are expected to take to the streets in what have become weekly protests against the Shiite-led government of Prime Minister Nouri al-Maliki.

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 twin bombings killed 15 people and left at least 40 wounded, officials said.

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

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.

In the evening, explosives hidden beneath produce in the back of a pickup truck exploded in the town of Mahmoudiya, about 30 kilometers south of Baghdad.