At least 70 people have been killed in a series of car bombs targeting mainly Shia areas in the Iraqi capital Baghdad, police said.
Many more were wounded as at least a dozen bombs hit busy shopping areas and markets in the city.
The day's deadliest attack happened when two bombs exploded in the eastern Habibiya neighbourhood, which is near the sprawling Shia district of Sadr City. That attack killed 12 and wounded 35.
Twin blasts also struck an open-air market in the predominantly Shia al-Maalif area, killing six and wounding 12 others.
Another car bomb exploded in the busy commercial Sadoun Street in central Baghdad. It killed five civilians and wounded 14 others. Among the wounded were four policemen.
The street is one of the major hubs in the capital for clinics, pharmacies and shops. Firefighters were seen struggling to extinguish the flames from the debris of the car bomb as police sealed off the area.
Elsewhere, police said a car bomb went off in the capital's eastern New Baghdad area as they were waiting for explosives experts to dismantle it, killing a civilian and wounding nine others.
The violence comes amid a recent marked rise in attacks linked to growing political and sectarian tension.
It has raised fears of a return to the levels of sectarian violence seen in 2006 and 2007, in which thousands died.
The bombs struck just a few hours after the ministry of interior released a statement saying that the violence in Iraq cannot be seen as sectarian in nature because the bombs do not distinguish between Sunnis and Shia.
Two weeks ago, 38 people were killed in a single attack targeting a Sunni mosque in eastern Iraq. Whoever is behind the attacks appears to be targeting different communities in turn, in order to maximise the perception that one attack is in response to the other.
Despite the persistent violence, there have been intensifying efforts on both sides of the divide to prevent a return to civil war.
One bombing struck the busy commercial Sadoun Street in central Baghdad. One bystander who saw that attack, Zein al-Abidin, said a four-year-old child was among the victims.
"What crime have those innocent people committed?" he asked.
Other neighbourhoods which were targeted include al-Maalif, where six died, and Habibiya, where 12 were killed.
No group has said it carried out the attacks, but tension between the Shia Muslim majority, which leads the government, and minority Sunnis has been growing since last year.
Sunnis have accused the government of Prime Minister Nouri Maliki of discriminating against them – something the government denies.