RAF Panavia Tornado GR4. Adrian Pingstone via Wikimedia Commons Editor's note: The original version of this report based on a Sunday Times article states that Royal Air Force pilots have been given the green light to shoot down Russian jets in Syria and Iraq if they feel endangered by them. The UK government has since denied that British planes in Iraq are armed with air-to-air missiles to counter potential Russian aerial attacks.

A spokeswoman from the Foreign & Commonwealth Office said: "We can confirm that our Moscow Defence Attaché met the Russian Ministry of Defence on 11 October. The Russian government sought clarification over inaccurate newspaper reports concerning RAF rules of engagement in Iraq. The Defence Attaché reiterated the British Government's concerns about Russia's military operation in Syria, including targeting legitimate opposition groups, using unguided weaponry and leading to large numbers of civilian deaths."

The original version of this article is below. The Sunday Times' original report can be found here.

As relations between the West and Russia steadily deteriorate, Royal Air Force pilots have been given the go-ahead to shoot down Russian military jets when flying missions over Syria and Iraq if they are endangered by them.

The development comes with warnings that the UK and Russia are now "one step closer" to being at war.

RAF Tornado pilots have been instructed to avoid contact with Russian aircraft while engaged in missions for Operation Shader — the codename for the RAF's anti-ISIS work in Iraq and Syria.

But their aircraft have been armed with air-to-air missiles and the pilots have been given the green light to defend themselves if they are threatened by Russian pilots.

"The first thing a British pilot will do is to try to avoid a situation where an air-to-air attack is likely to occur — you avoid an area if there is Russian activity," an unidentified source from the UK's Permanent Joint Headquarters told the Sunday Times. "But if a pilot is fired on or believes he is about to be fired on, he can defend himself. We now have a situation where a single pilot, irrespective of nationality, can have a strategic impact on future events."

The RAF Tornado aircraft will be armed with heat-seeking Advanced Short Range Air-to-Air Missiles — ASRAAMs, also called AIM-132 missiles. These weapons, which cost 200,000 pounds each, can reach triple the speed of sound and have a longer range than other air-to-air missiles, allowing RAF pilots to shoot down enemy aircraft without being targeted themselves.

The Sunday Times' report quoted a defence source as saying: "Up till now RAF Tornados have been equipped with 500lb satellite-guided bombs — there has been no or little air-to-air threat. But in the last week the situation has changed. We need to respond accordingly."

Raf tornadoes have been given the green light to engage Russian combat planes in Syria, like the su-34s pictured above. Mil.ru. via Wikimedia Commons

"We need to protect our pilots but at the same time we're taking a step closer to war," said another source. "It will only take one plane to be shot down in an air-to-air battle and the whole landscape will change."

Russia in Syria

The move comes after Russia's entry into the civil war in Syria in support of President Bashar al-Assad's government forces. The US has branded Russia's involvement as "fundamentally flawed," with the Kremlin facing accusations that it is ignoring ISIS fighters to go after Assad's opponents.

Institute for the Study of War

According to a report in the Sunday Times, an appraisal carried out by UK defense officials said: "It took six days for Russia to strike any Isis targets at all. Their air strikes have included moderate opposition groups who have been fighting to defend their areas from Isis. Among the targets hit were three field hospitals."

In the past 24 hours Russia's Defense Ministry said that it has continued its air strikes on ISIS positions in Hama, Idlib, Latakia, and Raqqa. It reported that the attacks resulted in the "complete destruction" of "53 fortified areas and strong points with armament and military hardware," seven ammunition depots, four field camps of "terrorists," one command center, and artillery and mortar batteries.

On September 28, when speaking to the US state-run Radio Free Europe/Radio Liberty, Putin ruled out sending ground troops to Syria, saying that it was "out of [the] question."