More from the New York Times:
The worst of the violence occurred in the northern city of Kirkuk, an ethnically divided flashpoint for struggles over control of Iraq’s oil resources. Ten people were killed there when an explosion rocked a police station. The other attacks occurred in the Shiite shrine city of Karbala, where 10 deaths were also reported; the city of Samarra, also the site of a revered Shiite shrine; and the Allawi neighborhood in Baghdad.
There were no immediate claims of responsibility and some news reports put the death toll sharply higher.
Iraq’s government has been seeking to tighten security in the capital as it prepares to host a meeting of Arab leaders beginning one week from Tuesday.