RAF bombing raids on oil wells in eastern Syria have dealt a "real blow" to the financing of terror group Islamic State, Defence Secretary Michael Fallon has said.
Mr Fallon confirmed that he personally approved the targets in the Omar oil field before Wednesday night's House of Commons vote, and gave final permission for the raid to go ahead after MPs had given their approval for the extension of air strikes from Iraq into Syria.
The Defence Secretary indicated that military action against IS - also known as Isil, Isis and Daesh - can be expected to continue for years, rather than months, telling BBC1's Breakfast: "This is not going to be quick."
Mr Fallon said: "I can confirm that four British Tornados were in action after the vote last night attacking oil fields in eastern Syria - the Omar oil fields - from which the Daesh terrorists receive a huge part of their revenue."
He added: "This strikes a very real blow at the oil and the revenue on which the Daesh terrorists depend."