At least 15 members of Iraqi security forces were killed and a further 22 wounded Sunday after a multiple-suicide attack on a military base north of Baghdad, local security sources reported.

Two bombers detonated vehicle-borne explosives at the western gate of Camp Speicher, a former U.S. base outside the Sunni city of Tikrit.

NEWS: Iraq: 22 Killed in Islamic State Group Suicide Blast

While three other bombers blew themselves up after entering the section of the base where Iraqi police are being trained, police and military sources in the Salahuddin operations command said.

BREAKING: Suicide attacks by #IslamicState near #Iraq's Camp Speicher kills at least 15 security forces - report pic.twitter.com/1pX5cxCBdz — China Xinhua News (@XHNews) January 3, 2016

Since the deadly blasts the Islamic State group have claimed responsibility for the attacks via an online statement.

In the document, the militants said it targeted "trainers from the rejectionist army", a term used by the Sunni insurgents to describe Shiite Muslims.

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Fighting between Iraqi military and Sunni militants of the Islamic State group has escalated in recent months with Iraqi forces declaring the city of Ramadi in al-Anbar province liberated from the militant group last week.

However, since ridding the terrorist group’s stronghold in the area there have been a number of retaliation attacks by the extremists in the city.

Iraqi Defense Ministry said in a statement the Islamic State group had used 22 bombers in two recent failed attacks in Anbar. The military responded by killing at least 42 militants including the bombers, the ministry said.

An Iraqi forensic team extract the remains of the bodies belonging to Shi'ite soldiers from Camp Speicher killed by Islamic State militants in the former U.S. army base in Tikrit April 6, 2015. | Photo: Reuters

Camp Speicher was the scene of the Islamic State group’s massacre of 1,700 Shiite soldiers who were killed in mid-2014 as the militants advanced into Iraq from Syria.

The group killed the men after taking them prisoner at the base however only 400 bodies have been found since.

The attack is said to be symbolic of the Islamic State group’s brutality and hatred for Iraq's Shiite majority.

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