A car bomb exploded in a crowded marketplace in a mainly Shi’ite Muslim district of the Iraqi capital on Wednesday, killing at least 20 people, police and medical sources said.

A further 48 people were wounded by the blast in the Shurta neighbourhood of southwestern Baghdad.

No group immediately claimed responsibility for the attack, but Sunni Islamic State militants who control large parts of northern and western Iraq often target Shi’ites whom they denounce as “rejectionists”.

A massive blast that killed more than 100 people less than a week ago in the town of Khan Bani Saad was claimed by Islamic State.

Iraqi security forces and Shi’ite paramilitary groups are currently focused on the western province of Anbar, where they have been gearing up for an offensive to retake the mainly Sunni Muslim governorate - Iraq’s largest.

The United Nations said earlier this month that nearly 15,000 people had been killed in the 16-month period up to April 30.