BAGHDAD: A car-bombing Saturday in southeastern Baghdad killed at least 21 people and wounded at least 42 others, according to police and hospital officials.

The attack targeted Shia pilgrims walking to Baghdad's holy Kadhimiyah shrine, according to local police officials at the scene. But other Iraqi security officials say the attack targeted an open-air market. The two differing accounts could not be immediately reconciled.

The officials all spoke on condition of anonymity as they were not authorised to speak to the press.

Thousands of Shia pilgrims from across Iraq are expected to travel on foot to the shrine of 8th-century Imam Moussa al-Kadhim over the coming days to commemorate the anniversary of his death. While there was no immediate claim of responsibility for the attack, the militant Islamic State (IS) group has claimed similar attacks targeting Shia pilgrims and civilians in Baghdad's Shia neighbourhoods. IS views Shias as apostates deserving of death.

The attacks come amid a political crisis in Iraq as the country's Prime Minister Haider al-Abadi is under increasing public pressure after repeated failed attempts at political reform to combat corruption and waste.

While IS still controls large swaths of Iraq's west and north, the group has suffered a series of territorial losses over the past year. In the face of those losses, analysts and Iraqi security officials say the extremist group is increasingly turning to insurgent-style attacks in Baghdad and other areas far from the frontline fighting.

More than 40 civilians have been killed in high-profile bombings in Baghdad over the past month. On March 25 an IS-claimed suicide bombing attack on a stadium killed 29 and wounded 60.