Civilians inspect the site of a car bomb attack in Baghdad's Sadr City neighbourhood, Iraq. Picture: Karim Kadim

Baghdad -

A string of car bombings shook five Baghdad districts on Wednesday, killing 21 people and wounding more than 55, security officials said.

The bombs hit the areas of Kazimiyah, Barik Saadun, Tariyah and al-Shaab, which are mainly populated by members of the Shia majority, as well as an industrial area east of the Iraqi capital.

The attacks are the latest in a surge of violence ahead of parliamentary elections scheduled for April 30.

Prime Minister Nuri al-Maliki is seeking a third term as his Shi'a-led government faces increasing opposition from Sunni-dominated provinces. Iraq has seen almost daily attacks over the last year, mostly targeting security forces and Shi'a civilians.

The Sunni jihadist Islamic State in Iraq and the Levant has controlled the city of Fallujah and other areas in al-Anbar province, west of the capital, since early January.

According to UN estimates, 8 868 people were killed in violence in 2013, Iraq's highest annual death toll in five years. - Sapa-dpa