Iraq market blast death toll climbs to 73

With the overnight deaths of critically wounded, 73 have now died as a result of an IS market bomb attack in Baghdad.

A twin suicide bombing in a crowded market in Baghdad has killed at least 70 people. (AAP)

Iraqi officials say the death toll from back-to-back market bombings carried out by the Islamic State group in eastern Baghdad has climbed to 73.

Police and health officials say several of the critically wounded died overnight while 112 people remain in hospital.

Also, at least five people are still missing after Sunday's blast ripped through the crowded Mredi market in the Shiite district of Sadr City, followed by a suicide bombing amid the crowd that gathered at the site.

Three medical officials confirmed latest death toll and number of wounded. All officials spoke on condition of anonymity because they aren't authorised to talk to reporters.