Attacks by five suicide bombers on an Iraqi military base north of Baghdad have killed at least 15 Iraqi security forces and wounded 22 others.
Iraqi security officials said two of the bombers detonated their vehicle-borne explosives on January 3 at the western gate of Camp Speicher, a former U.S. base outside the city of Tikrit.
Three others detonated explosives after entering the section of the base where Iraqi police are being trained.
The Islamic State (IS) militant group, which controls swathes of Iraq's north and west, claimed responsibility for the attacks in a statement posted on the Internet by supporters.
The statement said IS militants targeted "trainers from the rejectionist army," a term used by the Sunni insurgents to describe Shi'ite Muslims.
The attack comes days after Iraqi security forces, backed by U.S.-led coalition air strikes, announced they had recaptured the city of Ramadi -- which was seized by IS militants during the summer of 2015.