Britain joined the U.S.-led air strikes against the Islamic State (IS) group in Syria on Thursday after the British Parliament gave the green light to extending the fight against the jihadist militants.   

The air strikes were focused on six targets in an oil field under IS control in eastern Syria, as part of a strategy to destroy a source of funding for the terror group, the BBC reported.

British Tornado GR4 fighter bombers took off from the Royal Air Force base at Akrotiri in Cyprus before dawn, hours after parliament in London voted 397-223 to support Prime Minister David Cameron's plan to extend air strikes from Iraq to Syria. Previously, the British contingent participated in strikes on Iraq but not Syria.

British defence secretary, Michael Fallon, told the BBC on Thursday that he had approved “a series of targets in the Omar oil fields, well heads... the Tornados were successful in striking those targets."

Fallon also said that eight more Royal Air Force jets – two Tornados and six Typhoons – were being sent to Akrotiri to join the air strikes.

“We are doubling our strike force. The additional eight aircraft being sent to Akrotiri are now in the air and on their way,” Fallon said.

David Cameron argued in the House of Commons on Wednesday that action against the "medieval monsters" of IS was legal and would "keep our country safe".

Cameron said that he welcomed the strong support across Parliament with MPs from six different parties backing "this necessary action".