LONDON (AFP) - Britain would "take similar action again", Defence Secretary Michael Fallon said on Tuesday (Sept 8) following controversy over an RAF drone strike that killed two British Islamic State in Iraq and Syria (ISIS) militants in Syria.

"There are other terrorists involved in other plots that may come to fruition over the next few weeks and months and we wouldn't hesitate to take similar action again," Fallon told BBC Radio 4's Today programme.

"It's extremely dangerous because these are attacks that have been and are being planned against major public events on our streets," he said.

"Government has a duty, where it has information and the ability to prevent such attacks, government has a duty to deal with it," he added.

The Aug 21 strike was revealed by Prime Minister David Cameron in a speech to parliament on Monday and was the first such military action by Britain.

The legality of the move was questioned by opposition MPs and rights campaigners but British tabloids cheered the strike with The Sun's front-page headline reading: "Wham! Bam! Thank You Cam!".

The strike was targeted at 21-year-old Reyaad Khan, who left home to join ISIS militants in 2013.

It also killed 26-year-old Briton Ruhul Amin and a third, unidentified IS militant.

The strike itself was authorised by Fallon while Cameron was away on a visit but the Daily Telegraph reported that the case to target Khan had been approved by the government earlier in the year.

Cameron stressed that the strike was justified as "an act of self-defence" because of an imminent terror plot being prepared by Khan and said it had sought legal consultation from the attorney general.