Two suicide bombers have killed at least 12 people in separate attacks targeting pro-government tribesmen in Yemen's volatile south, officials said. The government has said the attackers are from the Yemeni wing of al Qaeda, but analysts say other local Islamist groups may be at work. Tribesmen have sided with the army in an effort to flush Islamist militants out of the south, where the government's grip has been loosened during months of protests against President Ali Abdullah Saleh's 33-year rule.