Al-Qaida-linked militants in eastern Libya declared holy war — or jihad — on the local Islamic State affiliate after one of their senior leaders was killed Wednesday by masked gunmen, which set off clashes between the rival groups that left 11 people dead on both sides, including a top militant commander. The hours-long fighting in the eastern coastal city of Darna erupted after gunmen opened fire on Nasser Akr, an al-Qaida-inspired militant once held in the United Kingdom on terrorism charges. The 55-year-old veteran jihadi, who fought in Afghanistan, was killed along with his aide.