At least seven soldiers were killed when fighters of the Somalia-based Islamist group al-Shabaab stormed a jail in the semi-autonomous state of Puntland early on Friday, police and the group said.Al-Shabaab said it had freed at least 400 prisoners, many of them its members, in its assault on the main prison in Bosaso, Puntland's largest city, in the early hours of Friday. The authorities did not confirm that figure."Last night many well-armed men attacked us from various directions. We fought back, but finally they entered the central jail by force using explosions. They freed the prisoners and took most with them," Mohamed Abdi, a prison guard, told Reuters."There was a hellish battle... As I fought inside, we lost five soldiers."