Armed gunmen in Syria who carried out a wave of recent sectarian killings of the country’s Alawite minority were advised and overseen by government forces, according to evidence gathered by the BBC. One man, Abu Khalid, said he had travelled as a civilian fighter to the Mediterranean coastal village of Sanobar on 7 March, to help battle former regime insurgents. He filmed himself shooting dead a 64-year-old village resident, Mahmoud Yusef Mohammed, at the entrance to his house. Abu Khalid, who