Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. Naweed Hussain was killed by a US drone launched on RAF orders last spring. Last year his brother Nadeem was jailed for four years at Kingston Crown Court for sending the jihadi £4,000 in Syria.He is the third British extremist to have been deliberately targeted and killed in an operation involving the UK to be named, following the deaths of Reyaad Khan and Mohammed Emwazi, known as Jihadi John, in 2015. More than 20 fighters from Britain and other countries killed in Iraq and Syria since autumn 2014 either by the RAF or in a UK-led mission, sources told the Mail.A government spokesperson said: “The UK advises against all travel to Syria and is unable to verify these claims. Anyone who does travel to Syria, for whatever reason, is putting themselves in considerable danger – particularly if they are fighting for our enemies.”In the last month the RAF has carried out more than 20 strikes destroying pockets of enemy fighters, terrorist compounds and Isil drone operators.It comes as Defence Secretary Gavin Williamson said: “The UK will not be complacent when it comes to terrorism. We pledged to continue to fight terrorists until their poisonous global network is totally destroyed. Despite Daesh’s diminishing territory, it is hell-bent on directing and inspiring terrorist attacks worldwide – threatening our security at home and abroad. The threat they pose is evolving and intensifying but our resolve to defeat them will not fade.”RAF aircraft have carried out more than 1,700 strikes against Daesh in Iraq and Syria since 2014. A British Isil fighter who was plotting attacks on UK soil was reportedly killed in a targeted attack on the orders of the RAF.Naweed Hussain, 32, was killed last spring while fighting for Isil in its Raqqa stronghold in a US drone strike but now it’s been revealed his death was the result of a secret mission by British forces.The extremist, who calls himself Abu Usamah al-Britani, had repeatedly groomed young British girls to become jihadi brides over Skype.He left Coventry in 2015 to join Isil leaving his first wife and family behind.Security sources later uncovered a terror plot by Hussain to target a British museum involving grenades.Hussain was reportedly hunted down by UK forces in a covert mission.According to the Mail, the RAF then called in a US Predator drone, stationed in Creech Air Force Base, Nevada, which was in the best position to kill him at the time.