Somali authorities have arrested several military officers for allegedly helping a suicide bomber gain entry to a military academy in the capital Mogadishu this week and kill at least 30 soldiers, an officer said on Wednesday. The al-Qaeda-linked al-Shabaab group, which has been waging an insurgency against Somalia's national government since 2006, claimed responsibility for the attack at the Jale Siyaad military academy. The attack was one of the deadliest the group has carried out in years against a military target in Mogadishu.