Al-Qaeda's front group in Iraq has claimed a wave of bombings targeting Shiite areas of Baghdad that killed at least 21 people on Sunday, in the latest violence to hit Iraq as it struggles with protests and a political crisis.
The al-Qaeda-affiliated Islamic State of Iraq (ISI) claimed responsibility for the wave of bombings "and declared it came in revenge for alleged criminal acts by the Shiite-led government in Sunnis areas of the capital," said the SITE monitoring service, which tracks extremist Internet forums.

Three car bombs struck the sprawling Sadr City slum in the north of the city, car bombs exploded in Ameen, Al-Husseiniyah and Kamaliyah in the east, and a roadside bomb blew up in Karrada in central Baghdad, security and medics there said.

Another roadside device went off in Saidiyah in the capital's south.

Al-Qaeda's front group is widely seen as weaker than during the peak of Iraq's sectarian bloodshed from 2006 to 2008, but is still capable of carrying out mass-casualty attacks on a regular basis.