At least 33 people have been killed in three bomb attacks in Shia areas of Baghdad as residents distributed sweets for the Eid al-Ghadir Shia Muslim feast.

Monday’s attacks, at least two of which were carried out with suicide car bombs, happened in or near the frequently targeted, predominantly-Shia districts of Kadhimiyah and Sadr City, police said.

Al Jazeera's Imran Khan, reporting from Baghdad, said that the bombings followed a familiar pattern and ISIL, which is fighting in northern and western Iraq, has carried out many similar attacks in the last few months.

"No one has claimed the attacks but they do follow a pattern that are very familiar to us - when ISIL gets squeezed elsewhere they take out revenge with attacks in the capital."

In Monday's attacks, a suicide car bomb blew up at a security checkpoint on Aden square, at the entrance of the northwestern area of Kadhimiyah, killing 22 and wounding 41, a senior Baghdad police officer told the AFP news agency.

A bomb in the popular Mredi market in the northern Sadr City area killed three and wounded at least 21 people, the same source said.

In Habibiyah, on the southern edge of Sadr City, a suicide car bomb attack left at least eight dead and 25 others injured.

Sources at the interior ministry and in the capital's hospitals confirmed the casualty figures to Al Jazeera.

The bombs hit when the streets of Baghdad were at their busiest, between 6.00pm and 8.00pm.

The UN said more than 1,110 people were killed in acts of violence across Iraq in September. According to an AFP count, more than 350 have already been killed this month.