The RAF strike force attacking Islamic State is being doubled as British war planes struck the extremists in their Syrian heartlands for the first time.
Within an hour of Wednesday night's Commons vote authorising military action, the first Tornado GR4 fighter bombers were in the air heading for an IS-controlled oil field in eastern Syria.
And today two more Tornados and six Typhoons took off from their bases in the UK heading for RAF Akrotiri on Cyprus where the British strike force attacking IS - also referred to as Isil, Isis or Daesh - is based.
"We are doubling our strike force," Defence Secretary Michael Fallon told the BBC Radio 4 Today programme. "These are the aircraft that the coalition have been asking for."
Four Tornados carrying Paveway IV guided bombs took part in the first raids overnight, targeting the Omar oil field - close to the border with Iraq - which IS uses to help finance its operations.
In a statement, the Ministry of Defence said that the jets - supported by a Voyager air refuelling tanker, an unmanned Reaper drone and other coalition aircraft - had attack six targets.
"Carefully selected elements of the oilfield infrastructure were targeted, ensuring the strikes will have a significant impact on Daesh's ability to extract the oil to fund their terrorism," the statement said.
"By extending RAF offensive operations into Syria, our aircraft are now able to help dismantle the means by which Daesh plan, direct and sustain their campaign of terror.
"Before our aircrew conducted their attacks, as is normal they used the aircraft's advanced sensors to confirm that no civilians were in the proximity of the targets, who might be placed at risk. Our initial analysis of the operation indicates that the strikes were successful."
Mr Fallon said the operation had struck a "very real blow" at the oil revenues on which the terrorists depended.
"All four Tornados have now successfully returned and we will be assessing later this morning the actual damage done," he told the BBC.
"They were using Paveway munitions in an area of oil fields where there was simply oil infrastructure in eastern Syria, a long way from Raqqa itself, down near Iraq.
"It's a very good illustration of a target that is literally one side of the border and couldn't previously be attacked."
The operation followed a tumultuous day at Westminster which saw MPs vote decisively to extend air strikes against IS - which had been confined to Iraq - into Syria.
Sixty-six Labour MPs ignored pleas by their leader Jeremy Corbyn to oppose further military action and voted for air strikes helping to deliver a Government majority of 174.
They included shadow foreign secretary Hilary Benn who rallied support to strike the "fascists" of IS in a powerful closing speech which drew a rare round of applause from MPs on both sides of the House.
Mr Fallon said the vote meant that Britain could finally play a full part in the US-led coalition attacking IS.
"What was really important about the vote last night was that it confirmed that Britain is a serious ally," he said.
"We have come to the aid of France, who requested us to help with our RAF planes, we have responded to the call from the United Nations on all members of the United Nations to do something to suppress this terrorism and eradicate the safe haven that Daesh has.
"We ended up with a strong and very decisive vote in favour of action and I hope everybody now will rally round that action and support the RAF in their efforts to keep our country safe."