British Prime Minister David Cameron has called the Russian military intervention in Syria a "terrible mistake."
Speaking to the BBC on Sunday, Cameron warned the Russian intervention in support of Syrian regime leader Bashar al Assad would only destabilize the region even more.
"They are backing the butcher Assad, which is a terrible mistake for them and for the world. It's going to make the region more unstable," Cameron said during an annual conference of his Conservative Party in the city of Manchester.
He also noted that most Russian air strikes in Syria have so far targeted territories held by opposition forces and not ISIS militants.
Cameron’s comments come after his Defence Secretary Michael Fallon claimed on Saturday in an interview with The Sun newspaper that British intelligence service observations suggest only one out of 20 Russian air strikes in Syria have actually targeted ISIS militants, while the rest were targeted at ISIS-free areas, killing civilians and factions fighting Assad’s regime.
“We’re analyzing where the strikes are going every morning,” he said. “The vast majority are not against ISIS at all."
“Our evidence indicates they are dropping unguided munitions in civilian areas, killing civilians, and they are dropping them against the Free Syrian forces fighting Assad.”
Fallon also argued that Russian President Vladimir Putin was “shoring up Assad and perpetuating the suffering” and that the change in Syria’s current circumstances would not avert the British government from pressing ahead with fighting to extend air strikes into Syria.
The UK, US, France, Germany, Qatar, Saudi Arabia and Turkey have all condemned the Russia’s intervention in Syria, stating that it was clearly not targeting ISIS.
“We express our deep concern with regard to the Russian military build-up in Syria and especially the attacks by the Russian air force on Hama, Homs and Idlib which led to civilian casualties and did not target Daesh,” they all said in a joint statement.
“These military actions constitute a further escalation and will only fuel more extremism and radicalization. We call on the Russian Federation to immediately cease its attacks on the Syrian opposition and civilians and to focus its efforts on fighting ISIS.”
Although Russia initially claimed its air strikes are being targeted against the ISIS militant group, with Russian Foreign Minister Sergei Lavrov dismissing rumours that the air strikes were targeting opposition forces as “unfounded,” Lavrov later told reporters on Thursday that other groups besides ISIS were also being targeted by the air strikes.
"I would recall that we always were saying that we are going to fight ISIS and other terrorist groups, this is the same position that the Americans are taking, the representatives of the coalition command have always been saying that their targets are ISIS, Al Nusra and other terrorist groups," Lavrov said.
“If it looks like a terrorist, if it acts like a terrorist, if it walks like a terrorist, if it fights like a terrorist, it's a terrorist, right? This is basically our position, as well. We see eye-to-eye with the coalition on this one."
Dmitry Peskov, the spokesman for Russian President Vladimir Putin, also confirmed on Thursday that other groups were also targeted.
"The goal [of the Russian operation] is to help the Syrian armed forces in their weak spots in the fight against ISIS and other terrorist and extremist groups," he was quoted saying in Russian media.
“These organizations are well known and the targets are chosen in coordination with the armed forces of Syria,” Peskov added.
US Senator John McCain, who heads the Senate’s Armed Services Committee, confirmed on Thursday that Russia had hit CIA-backed opposition forces instead of ISIS militants.
"I can absolutely confirm to you that they were strikes against our Free Syrian Army recruits that have been armed and trained by the CIA because we have communications with people there," McCain said.
The commanders of Tajamaa al Ezza and Liwa Suqour al Jabal, both opposition groups affiliated with the US-backed Free Syrian Army (FSA), claimed their positions were targeted by Russian missiles in the northwestern governorates of Hama and Idlib respectively.
Russian Foreign Minister Sergei Lavrov, on the other hand, denied air strikes were targeting the Free Syrian Army. “We don’t consider Free Syrian Army a terrorist group, and believe [it] should be part of the political process,” he told reporters in New York.
Putin’s spokesperson Peskov, however, on Wednesday questioned the existence of the Free Syrian Army, saying “does it exist, the Free Syrian Army? Haven’t most of them switched to ISIS group? It existed but whether it does now nobody knows for sure, it’s a relative concept.”
Russia began building up its military presence in Syria’s coastal governorate of Latakia - a stronghold of the regime and Assad’s minority Alawite sect - where they have reportedly deployed military experts and aid to assist the Assad regime.
It has also been reported that Russia is expanding its only Mediterranean naval base in Tartus and is building an airstrip in Latakia’s Bassel al Assad airport, making it the biggest foreign mission launched by Moscow since the invasion of Afghanistan in 1979.
In recent weeks, US and Russian officials have repeatedly voiced the need for coordination between the two superpowers in their separate military operations in Syria to avoid directly clashing with each other.
The US has already been leading a coalition of over 60 nations against ISIS for a year, but key differences over a new transition phase aimed at ending the four-and-a-half-year-old Syrian conflict have prevented Russia from joining the coalition.
While the US is adamant that Assad must not be included in the solution process, Russia insists the embattled regime leader should play a role in the transition phase. Washington has warned Moscow that attempts to support the Assad regime will be counterproductive and will only fuel the rise of militant groups like ISIS.
To date, the war in Syria has killed an estimated quarter of a million people with most of the casualties occurring as a result of regime air strikes and barrel bombings of civilian areas. As much as half the country’s population has also been displaced, both internally and externally.