The leader of a Yemeni al-Qaeda cell has been killed in clashes with security forces, Yemen's state news agency has said. The agency said the home of the militant, identified by the governor of Yemen's Shabwa province as Abdullah al-Mehdarhad, was surrounded by security forces on Tuesday and that he was killed as a result of an exchange of fire. Yemen, the Arab world's poorest nation, came to the foreground of US-led efforts to battle Islamist militants after the Yemen-based wing of al Qaeda said it was behind a failed Dec. 25 plot to bomb a US-bound airliner.