Militants have unleashed attacks on Iraq’s majority Shia community, killing at least 33 people.
The attacks are the latest in relentless assaults that have challenged the Shia-led government as it battles the Sunni-led insurgency by the Islamic State group.
A suicide bomber hit a mosque in Baghdad as Shia worshippers left after noon prayers, killing 17 people, while a triple car bombing in the holy city of Karbala killed 16.
Iraq has been plunged into its worst crisis since the US troops left at the end of 2011 in the wake of the blitz by IS militants this summer.
The extremist group captured large chunks of land in western and northern Iraq, carving out a proto-state on the territory it controls between Syria and Iraq and imposing its own harsh interpretation of Islamic law, or Shariah.
Since August, US warplanes have been carrying out air strikes against the group as Iraqi and Kurdish security forces work to retake territory it has seized.
In Baghdad, the bomber blew himself up among Shia worshippers as they were leaving a mosque in a commercial area in the city centre after midday prayers, killing at least 17 people and wounding 28, a police officer said.
In Karbala, three separate car bombs went off simultaneously, killing at least 16 people and wounding 41, another police officer said. The city, about 90 kilometres (55 miles) south of Baghdad, is home to the tombs of two most revered Shia imams and the site of year-round pilgrimages. The explosives-laden cars were parked in commercial areas and car parks near government offices, the officer added.
Medical officials confirmed the casualty figures.
The attacks in Baghdad and Karbala came a day after a suicide bombing targeted another Shia mosque in the Iraqi capital, in the western Harithiya neighbourhood, killing 28 people.
No one immediately claimed responsibility for the latest attacks but they bore the hallmarks of the al Qaida-breakaway Islamic State group, which has recently claimed several other large bombings in Baghdad and elsewhere, particularly in Shia areas.