A suicide bomber blew himself up in a cafe in the northern Iraqi city of Kirkuk late Friday, killing 38 people and wounding 26.
Customers were enjoying food and tea to break their daily Ramadan fast when, according to one witness, a heavyset man strolled in and yelled "Allahu akbar" and set off the bomb. No one has claimed responsibility.
The bombing culminated a violent two days in Iraq that left around 60 people dead.
There appears to be no let up in the violence between Shi'ites and minority Sunnis, which the United Nations says has killed more than 2,500 people since April.
The Associated Press reports Sunni and Shi'ite clerics delivered a joint Ramadan sermon Friday in Baghdad, calling for an end to the violence and a united Iraq.
Iraqi Sunnis complain that the Shi'ite-led government ignores their needs and is marginalizing them politically.