The bombing targeted the premises of the Patriotic Union of Kurdistan in east Baquba city, the capital of Diyala province, the Kuwait news agency KUNA reported.
A police official told KUNA that the death toll is likely to rise as some of those injured are in critical condition.
The explosion came during a time of high tensions between the Kurdistan Regional Government and the government of Iraq over the disputed oil-rich city of Kirkuk.
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