Three car bomb blasts targeting key buildings in the Kurdish-controlled Iraqi town of Qara Tapah killed at least 20 people on Sunday, the mayor and security sources said.
"At 10:30 this morning (0730 GMT), three car bombs struck Qara Tapah, killing 20 people and wounding 10," said Mayor Wahab Ahmed, who was lightly wounded in the attack.
Qara Tapah lies close to Jalawla, a key battleground northeast of Baghdad between pro-government forces and Islamic State group (IS) jihadists.
The mayor said the three car bombs targeted his office, a building used by the Kurds' asayesh internal security service and an office of the Patriotic Union of Kurdistan party.
Wahab Ahmed said nearby buildings used by the electricity department and the Kurdish peshmerga forces' veterans affairs bureau were also damaged in the explosions.
"Some people are still stuck in the wreckage," he said.
Sources in the peshmerga and a local council member confirmed the death toll.
Confessionally and ethnically mixed Diyala province, which borders Iran, has seen intense fighting pitting militants of IS against Iraqi federal troops, and their Kurdish and Shiite militia allies.