The mission to target so-called IS militants in Syria could take some time and will require persistence, PM David Cameron has said. RAF Tornados conducted air strikes on six targets in Syria, "successfully" attacking an IS-controlled oilfield on Thursday, the Ministry of Defence said. There will be "strong support from our allies" for the action, the PM added. Two more Tornados and six Typhoons have arrived at RAF Akrotiri, in Cyprus, from where they will join the attacks. Speaking after the strikes, Mr Cameron said the operation in Syria would require "patience". "It is complex and it is difficult what we are asking our pilots to do, and our thoughts should be with them and their families as they commence this important work," he said. The decision to approve the mission was "good for the country", the prime minister said, adding: "There was a compelling case for extending our air strikes from Iraq to Syria, and I was glad to see such strong support right across parliament." MPs overwhelmingly backed UK military action against IS in Syria, by 397 votes to 223, after a 10-hour Commons debate on Wednesday. Former Prime Minister Tony Blair has welcomed the result of the vote, saying European forces had to lead the response to the threat. Delivering the Kissinger Lecture at the Library of Congress in Washington, Mr Blair said: "We should learn the lessons of the whole period from 9/11 to today and try to forge a new synthesis of foreign policy which recognises the need for an active policy of engagement, but in a way sophisticated by our experience, not incapacitated by it. "For Europe, there is a huge calculation to be made. This security threat is at our door. It is actually within our home." He added that there was "no doubt" in his mind that "this is a battle we will win". Defence Secretary Michael Fallon said the MoD would be assessing the damage done by the first strikes, saying he had personally approved the targets ahead of the Commons vote. He said the aim was to strike "a very real blow on the oil and revenue on which Daesh depends". A White House spokesman welcomed Parliament's approval of action in Syria, saying "we congratulate the UK on the strikes overnight". However, Russian Foreign Minister Sergei Lavrov said the UK was obliged under the terms of the UN Security Council resolution on dealing with IS to coordinate with Syrian President Bashar al-Assad on air strikes in the country. 'Urgency' over oilfields BBC security correspondent Frank Gardner said the IS-controlled Omar oilfield in eastern Syria - hit by UK air strikes - was one of eight oilfields targeted by coalition forces. He said the decision to target oilfields may have been a political one - to avoid civilian casualties. But our correspondent said there was now "an urgency" among US-led forces to "close down" IS sources of revenue. The oilfield at Omar potentially represents more than 10% of its income, the MoD said. Mr Fallon also confirmed two Tornados and six Typhoons were being sent to join the eight jets already at the RAF Akrotiri base in Cyprus, from where UK operations in Iraq have been launched. The Typhoons left RAF Lossiemouth in Moray, Scotland, to join the air strikes.