LONDON • Britain will not hesitate to carry out more deadly drone strikes against militants in Syria who are planning attacks on the country, said Defence Minister Michael Fallon yesterday, as he defended the killing of two British nationals fighting with the militant Islamic State in Iraq and Syria (ISIS).

Prime Minister David Cameron told Parliament on Monday that he had approved an air strike against a vehicle carrying a British fighter, Reyaad Khan, in Syria who he said was plotting attacks against Britain. Mr Cameron said the Attorney-General had been consulted and that Britain was exercising its "inherent right to self-defence".

"In this area, there is no government we can work with. We have no military on the ground to detain those preparing plots," he said.

The hit also killed Briton Ruhul Amin, and another ISIS fighter.

"We wouldn't hesitate to do it again. If we know there's an armed attack likely, if we know who's involved in it, we have to do something," Mr Fallon told BBC Radio.

Human rights groups and some lawyers criticised the decision to authorise the strike, which was carried out in August, saying the British government had to give details about the evidence it had, and to disclose the legal basis for the attack.

They said the action mimicked the controversial drone strike policy of the United States and blurred the lines on what Britain was prepared to use such tactics for.

"The fact that David Cameron has bypassed Parliament to commit these covert strikes is deeply worrying - as is his refusal to share what legal advice he was given," said rights group Reprieve's legal director Kat Craig.

The opposition Labour Party said the decision should be subject to an independent review, and asked for more information on the legal advice the government had received.

Mr Jeremy Corbyn, an anti-war protester and the favourite to be named as Labour's next leader on Saturday, said the decision needed to be given "urgent consideration".

Mr Fallon declined to give details on what evidence London had of plots against Britain or how many other targets it had identified that could be attacked in the same way.

British officials did not offer a specific explanation for the delay of more than two weeks in reporting the lethal drone operation. Nor did they say how they knew two of the victims were Britons.

"This announcement by the Prime Minister is a big departure in a number of ways," said Mr Michael Clarke, director-general of the Royal United Services Institute, a research group that specialises in defence issues, who noted that Britain had so far promised not to conduct military operations in Syria.

In addition, Mr Clarke said, "this drone strike is the first to have been conducted, apparently, as a targeted assassination".

Since its election in May, the British government has been expected to make another attempt to get the approval of lawmakers for military action in Syria.

Mr Clarke said the drone killings will be seen "as jumping the parliamentary gun" in announcing that British air power had been used to bomb something on the ground in Syria. He added that this may prove to be a "high-risk strategy".

The decision to target Khan was made at a National Security Council meeting attended by Mr Cameron, his office said. Approval for the specific operation that killed Khan was given by Mr Fallon.

Mr Cameron's announcement came as France said it would start sending reconnaissance flights over Syria and was considering launching air strikes against ISIS in Syrian territory.

The French move to begin surveillance missions over Syria from yesterday was announced by President Francois Hollande at a news conference in Paris on Monday.

"Depending on the information that we will have gathered, the intelligence that we will have collected, and the reconnaissance that we will have done, we will be ready to conduct air strikes," Mr Hollande said.

But sending French troops to Syria was "unrealistic" and "reckless", he added, in ruling out ordering any ground forces to Syria or Iraq, where he said France had already conducted 200 air strikes.

Britain is not taking part in military action in Syria, because lawmakers rejected that idea two years ago, although both Britain and France are involved in the US-led campaign to strike ISIS targets in Iraq.

REUTERS, NEW YORK TIMES