SOMALIA'S army and allied clan militias have killed at least 100 al Shabaab fighters in heavy clashes in the central Hiran region, the defence ministry said, days after twin bombings killed at least 120 people in the capital. Al Shabaab, an al Qaeda franchise, claimed responsibility for two car bombs that blew up outside the education ministry in Mogadishu on October 29, the deadliest incident since a truck bomb killed more than 500 people at the same location five years previously. The Islamist group have killed tens of thousands of people in bombings since 2006 in their fight to overthrow…