Two Turkmen leaders were among those killed when a suicide bomber blew himself up amid a group of demonstrations protesting the lack of security in Tuz Khurmatu, Today's Zaman reported Wednesday.
Many other people were injured.
The two leaders were identified as Ahmed Abdel-Wahed and Ali Hashem Mukhtar Oglou.
Ankara officials said it is clear a spate of attacks, lately centered in Tuz Khurmatu, are aimed at sparking ethnic and sectarian conflict by targeting "unarmed Turkmen brothers."
The Turkish Foreign Ministry said Turkey was ready to provide necessary assistance to the people of Iraq, the Hurriet Daily News reported.
There had been no claim of responsibility for the attacks.
Tuz Khurmatu, 124 miles north of Baghdad, sits in a band of territory contested by Arabs, Kurds and Turkmen.