A Yemeni health official says a car bomb outside the gate of a presidential compound in a southern city has killed at least 21 people, hours after the country's new president was formally inaugurated. The health official said the fatalities in the blast Saturday in the city of al-Mukalla were presidential guards. A security official said it was a suicide blast. He did not provide a death toll. Both officials spoke on condition of anonymity as they were not allowed to speak to the press.