RAF fighter jets targeted another Syrian oilfield during the second combat sortie from the British base in Cyprus last night, Defence Secretary Michael Fallon has confirmed.
Typhoons from RAF Lossiemouth in Scotland and unmanned Reaper aircraft were used for the first time last night, alongside the RAF's Tornados, in an effort to cut off the financial supply to Islamic State (IS).
Mr Fallon was speaking during a visit to RAF Akrotiri, where he thanked military personnel for their commitment to tackling the terrorist threat in Syria and Iraq.
But he could make no assurances about the length of the campaign, telling them only that it would not be short. And he denied the suggestion that the military were avoiding going for IS leaders after a second strike on infrastructure rather than personnel.
He told the Press Association: "Last night we saw the RAF Typhoons, which have only just arrived here from Scotland, striking successfully for the first time within 24 hours or so of their arrival, which is a pretty impressive achievement.
"Last night saw the full force of the RAF."
The strikes came after Wednesday's historic vote in Parliament to sanction military action, despite thousands of people protesting during anti-war demos.
Mr Fallon said: "They (the military) have the support of Parliament, Parliament represents the public. You have support across the political spectrum from all sides and a clear decisive majority.
"You will always find in a democracy there will be some who oppose military action. That's the whole point of being a democracy. But there was an overwhelming vote in Parliament that it made no sense to restrict the RAF to striking on one side of a border that the terrorists themselves don't recognise."
Asked if the military were asked to target areas with a low risk of civilian casualties to appease public dissent in the UK, Mr Fallon said: "Nobody likes strikes, nobody likes warfare, but when you're dealing with people who are not negotiating with you but simply want to kill as many Westerners or Brits as possible, then you have to use force.
"We are going to use force against them in the headquarters, their command and control, their logistics, but also in the infrastructure that supports them.
"We are going to do our very best to minimise civilian casualties."
He told crews at RAF Akrotiri that it was a "privilege" to thank them "for what you have been doing, and what you are about to do".
He said the expansion of the strike force had been "seamless" and that their work was valued by Parliament and the people of the UK.
Speaking to around 200 crew in an aircraft hangar at the base, he said: "This is a very real threat to us in Britain. And it derives from Syria.
"You are now able to hit the Daesh on both sides of that border - Syria and in Iraq. And you are able to hit them harder. That's why we have doubled the strike force available to you.
"This campaign is not going to be short or simple. We face a new kind of enemy that makes no demands, takes no hostages, doesn't want to negotiate.
"It's not what we do that they oppose, it's what we are. We are people who choose our Government, accept a Rule of Law, tolerate other religions. It's because of who we are in Britain and the West that we have this particular death cult.
"You go now into this full-bodied mission with your orders and with your training. But I want you to know also you go with the backing of the Government and the people of Britain, and you go also with all out good wishes."
Last night British Typhoon fighters were deployed for the first time in the mission to defeat Islamic State in Syria and Iraq.
Two Typhoons and two Tornado jets were sent on a combat mission from the Akrotiri base.
The deployment came as Prime Minister David Cameron insisted British warplanes can help to bring about a political settlement in the civil war-torn country.
RAF Tornado fighter jets had already flown an armed patrol over the east of the country "gathering intelligence on terrorist activity", the Ministry of Defence said.
And in a continuation of operations in Iraq, two Tornados "silenced" a "terrorist" sniper team with a "direct hit" from a Paveway IV guided bomb, it added.
The number of fighter jets based at Akrotiri has been bolstered with reinforcements from Lossiemouth ahead of further sorties in Syria and continued raids in Iraq against IS, which is also known as Isis, Isil and Daesh.
But the Free Syrian Army opposition group has claimed British intervention is "just a few more jets" over the course of a long campaign.