Three bombings in Iraq's capital on Wednesday killed at least 12 people, including a suicide bombing in a mainly Shiite neighborhood that had been attacked the day before, Iraqi officials said.

Six civilians and two policemen were killed when the bomber rammed his explosives-laden car into the checkpoint in the al-Rashidiya district, a police officer said. Up to 23 other people were wounded, he added.

On Tuesday, at least 12 people were killed in a suicide car bombing at an outdoor vegetable and fruit market in al-Rashidiya.

Two separate bombings elsewhere in Baghdad killed four civilians and wounded 16, police said. Medical officials confirmed the casualties. All officials spoke on condition of anonymity as they are not authorized to talk to the media.

No one has claimed responsibility for the attacks, which bore the hallmarks of the Islamic State group. The Sunni extremists frequently launch attacks targeting Iraq's Shiite majority and the Shiite-led security forces.

IS has stepped up attacks in recent months as it has lost territory in northern and western Iraq that it had captured in 2014.

IS claimed a massive truck bombing in downtown Baghdad last week that killed 292 people, making it among the deadliest attacks in Iraq since the 2003 U.S.-led invasion. Last Thursday, an IS attack at a Shiite shrine north of Baghdad killed 37 people.

Wednesday's bombings came on the eve of a military parade in Baghdad planned for Thursday to mark the anniversary of the 1958 overthrow of a Hashemite monarchy and the declaration of Iraq as a republic.