TRIPOLI - Islamist gunmen have stormed a military arms depot in Libya and a nearby port and seized numerous weapons and army vehicles after killing four soldiers, a security official said on Sunday. The group also took several hostages, both soldiers and civilians, and is "threatening to execute them unless a siege by security forces is lifted" in Al-Baida, the official said, asking not to be named. "This criminal gang assaulted an army weapons depot and seized 250 weapons, killed four soldiers and wounded 16 others" in the Wednesday operation in Derna, which lies east of Al-Baida and 1,300 kilometres...