Britain has killed two of its own nationals accused of fighting for the Islamic State of Iraq and the Levant (ISIL), and plotting attacks on British soil, in its first air strike in Syria, Prime Minister David Cameron announced.

Despite not having a parliamentary mandate to take military action in Syria, Cameron told politicians on Monday that, as an act of self-defence, Briton Reyaad Khan had been targeted and killed in a precision drone strike in the country. Cameron said the strike was carried out by a British Royal Air Force (RAF) remotely piloted aircraft in August and that two people travelling with the man, including another Briton, Ruhul Amin, were also killed.

“There was a terrorist directing murder on our streets and no other means to stop him,” Cameron said. “We took this action because there was no alternative.”

The strike was approved by the attorney general – the main legal adviser to the UK, said Al Jazeera’s Emma Hayward, reporting from London.

A third Briton fighting with ISIL, Junaid Hussain, was killed in a separate US air strike in August, Cameron said.

Cameron said both Khan and Hussain had been involved in “plots to attack high profile public commemorations, including those taking place this summer”. (Al Jazeera)