A series of co-ordinated bombings in the Iraqi capital Baghdad has killed at least 68 people and wounded dozens more, police and medical sources say.
The bombs targeted mainly Shia neighbourhoods during the rush hour.
The deadliest explosion was reported to be in Jisr Diyala in south-eastern Baghdad, where a car bomb killed at least seven people.
Violence has increased in Iraq in recent months amid heightened tensions between Sunni and Shia Muslims.
Several blasts in the northern district of Kadhimiya killed at least five people and wounded many others, according to reports. The northern suburb of Sadr City was also attacked.
At least 10 separate bombings are believed to have taken place on Wednesday. More than 200 people were injured.
The interior ministry, which described the attacks as "terrorist explosions", put the casualty figure considerably lower, at 20 dead.
No group has admitted carrying out the bombings, but correspondents say they appear to have been the work of Sunni militants.
Sunnis say they are being marginalised by Prime Minister Nouri Maliki's Shia-led government.
Correspondents say deep-rooted sectarian tensions have also been aggravated by the civil war in neighbouring Syria.
More than 4,000 civilians have been killed and 10,000 more have been wounded so far this year, with Baghdad province worst hit.
Casualty figures released by the United Nations showed 1,057 Iraqis - most of them civilians - were killed in July, making it the deadliest month in the country for years.
The authorities have stepped up security operations in Baghdad, according to BBC World Service Middle East editor Sebastian Usher. But they seem unable to stop the growing intensity of violence now back to a level not seen for five years, he says.
Barely a day goes by in Iraq now without similar bloodshed, our correspondent adds.
The scale of bloodshed peaked in Iraq at the height of the insurgency in 2006-7.