Mogadishu (RHC)-- A suicide bomber disguised as a policeman blew himself up inside a police training camp in Somalia’s capital Mogadishu on Thursday and killed at least 15 officers, officials said.

A police spokesman said the attacker had explosives strapped to his body and infiltrated the General Kahiye Police Training Academy during an early morning parade.

Preliminary reports state that so far 15 people have died and 17 others were injured.

The militant Islamist group al Shabaab claimed responsibility for the attack and gave a higher death toll.

The group, which is allied to al Qaeda, is waging an insurgency against the U.N.-backed government and its African Union allies in a bid to topple the weak administration and impose its own strict interpretation of Islam.

The militants were driven out of Mogadishu in 2011 and have since been steadily losing territory to the combined forces of African Union peacekeepers and Somali security forces.

Al Shabaab’s attacks come at a time when the African Union is finalizing plans to trim its peacekeeping mission called AMISOM