At least 12 Islamic State fanatics have been killed in Russia's first air strikes on the extremist faction's main Syrian stronghold.

Russia's defence ministry said it struck an ISIS training camp near the village of Maadan Jadid, 45 miles east of Raqqa city and 'a camouflaged command post at Kasrat Faraj' southwest of the city.

On the third straight day of airstrikes, Russian warplanes mainly struck areas held by rival insurgent groups rather than the Islamic State fighters - drawing an increasingly angry response from the West.

ISIS militants posted a tweet warning 'Death to Putin: We are coming #soon' with a picture of Moscow's St Basil's Cathedral in flames, according to the SITE intelligence group.

Meanwhile, Russian President Vladimir Putin arrived for talks with his French counterpart Francois Hollande in Paris as questions mount over who Moscow was targeting in Syria.

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Wiped out: Footage taken from Russian Defense Ministry official shows the latest airstrikes in Syria which have finally started to target Islamic State positions near its de facto capital Raqqa, killing at least 12 jihadis

Russia's defence ministry said its fighter jets struck 'an ISIS training camp near the village of Maadan Jadid' around 45 miles east of Raqqa city and 'a camouflaged command post at Kasrat Faraj' southwest of the city

Syrians stand next to a crater caused by what activists said was a Russian air strike in Latamneh city in the northern countryside of Hama

War of words: News of the Russian strikes against the jihadists came as ISIS militants posted a tweet warning 'Death to Putin: We are coming #soon' with an image of Moscow's St Basil's Cathedral in flames (above)

The two leaders smiled as they shook hands outside the Elysee palace where they will discuss the conflict in Syria before a four-way summit with Germany on the crisis in Ukraine.

The Syrian Observatory for Human Rights (SOHR) said the latest strikes had killed at least a dozen ISIS fighters late on Thursday.

'Last night, Russian strikes on the western edges of Raqqa city, and near the Tabqa military airport, killed 12 ISIS jihadists,' Observatory head Rami Abdel Rahman said on Friday.

He said their bodies were transported to a hospital in the province.

Moscow's defence ministry said Friday claimed its war planes had 'conducted 18 sorties on 12 positions held by the Islamic State terrorist group in Syria' since Thursday, although some of these were disputed by civilians and the Syrian opposition.

The statement said Russian raids also destroyed 'a command post and communications centre' held by ISIS in Daret Ezza in northern Aleppo province, as well as bunkers and weapons depots in Maaret al-Numan and Habeet in northwest Idlib province.

Tense: French President Francois Hollande, left, greets Vladimir Putin upon his arrival at the Elysee Palace as the Russian President comes face to face with Western leaders for the first time it began bombing Syria

(From left) Russian Foreign Minister Sergey Lavrov, Russian President Vladimir Putin, French President Francois Hollande and French Foreign Minister Laurent Fabius meet for talks at the Elysee Palace in Paris

Warm welcome: French President Francois Hollande greets German Chancellor Angela Merkel upon her arrival at the Elysee Palace in Paris for a peace summit on the Ukraine conflict with Western leaders

MIDDLE EAST'S MELTING POT OF CHAOS: WHO'S FIGHTING WHO... AND WHY A graphic showing who is fighting who in the Middle East and why. The conflict has become so complex that arch enemies are finding their interests have aligned, presenting diplomatic and military conundrums WHAT FACTIONS ARE FIGHTING IN SYRIA? Islamic State A mainly Sunni Islamist terror group, including tens of thousands of foreign fighters, which has moved into large swathes of Syria. Syrian government Bashar al-Assad is believed to have used chemical weapons against his people. His government considers all rebel groups terrorists. Moderate Syrian rebels Backed by the West. Known as the Free Syrian Army. Jadhat al-Nusra An extremist rebel group affiliated with Al Qaeda. Hezbollah Lebanon’s Shi'ite group Hezbollah, backed by Iran, fights with the Syrian army. Islamic Front An alliance of seven rebel groups who want to create an Islamic state but criticise ISIS for its brutal tactics. US, UK and other coalition forces The coalition forces are fighting to defeat ISIS and oust Assad. Coalition forces are in Turkey and Jordan training moderate Syrian rebels. Russia Vladimir Putin says Russia is attacking ISIS and supporting Assad. Evidence suggests it is attacking non-ISIS rebels. Iran Iranian troops are to join government forces and Hezbollah in a ground offensive backed by Russian air strikes. Iran wants to defeat ISIS and prop up Assad. Russia finally started blitzing Islamic State targets late last night and today, killing at least 12 jihadists after facing criticism from the West for attacking moderate rebels, many of whom are by the U.S.-led coalition Russia has been accused of only targeting areas controlled by U.S.-backed rebels and not the Islamic State on the first two days of its bombing campaign in Syria - as seen in the graphic above Advertisement

Raids also struck 'an ISIS command post' in Kafr Zeita in central Hama province.

According to the Observatory, none of these areas are controlled by ISIS, though most are held by Al-Qaeda's Syrian affiliate Al-Nusra Front.

And according to a Syrian military source, Russian strikes on Friday also targeted an ancient Christian town in Homs province seized by ISIS on August 5.

'Russian warplanes struck Al-Qaryatain this morning,' the source said.

Putin arrived in Paris for a peace summit on the Ukraine conflict, this morning, but Russia's dramatic intervention in Syria looks set to dominate as he holds one-on-one talks with French President Francois Hollande and German Chancellor Angela Merkel.

Ahead of the talks, a Putin ally and senior lawmaker warned the Russian air strikes will last for three to four months and will increase in intensity.

'There is always a risk of getting bogged down but in Moscow they're talking about three to four months of operations,' Alexei Pushkov, the head of the foreign affairs committee of Russia's lower house of parliament, told France's Europe 1 radio.

Indiscriminate: A video released by the Russian defence ministry appears to show the use of cluster bombs in Syria that pepper an area the size of a football field and which critics say leads to civilians being killed

Two children were the latest victims of Russia's airstrikes in Syria that have reportedly killed up to 36 civilians

Pushkov said more than 2,500 air strikes by the US-led coalition in Syria had failed to inflict significant damage on ISIS jihadists, but Russia's campaign would be more intensive.

'I think it's the intensity that is important. The US-led coalition has pretended to bomb Daesh (another name for Islamic State) for a year, without results.

'If you do it in a more efficient way, I think you'll see results,' he said.

Earlier, the SOHR claimed two children were the latest victims of Russia's airstrikes in Syria that have so far killed up to 36 civilians.

Reports of the deaths came as a U.S. general accused Moscow of using indiscriminate cluster bombs that can obliterate areas the size of football fields in its attacks on rebel groups.

The latest air strikes hit the district of Jabal al-Zawiya, in an area under the control of Al-Qaeda's affiliate in Syria and other Islamist rebel groups, according to a British-based monitoring group.

'Four civilians, including a child and a woman, were killed in raids conducted by Russian military aircraft,' said the Syrian Observatory for Human Rights.

'Three other civilians, including a girl and a woman, were killed in bombing by these planes of the village of Habeet,' in the same province that borders Turkey, said the group, which relies on a network of sources on the ground for its information.

Russian air strikes on Syria have killed 28 people since they were launched on Wednesday, says the Observatory.

Bombing campaign: Vladimir Putin has conscripted 150,000 new troops into the Russian army as the country unleashed a new wave of airstrikes in Syria, including rebel positions in Idlib pictured)

Blitzed: A man runs past a burning military vehicle at a base controlled by rebel fighters from the Ahrar al-Sham Movement targeted by what activists said were Russian airstrikes at Hass ancient cemeteries in Idlib

Syria's main opposition group accused Moscow of killing 36 civilians in the central province of Homs on Wednesday, but the Kremlin has denied any civilians were among the dead.

Meanwhile, Lt General Robert Otto, the deputy chief of staff for intelligence and surveillance for the Air Force, said the Russians have been dropping cluster bombs – also known as 'dumb bombs' – a reference to munitions that are not precision-guided.

The use of such indiscriminate targeting, he said, could kill innocent civilians, which may have the unintended consequence of creating more terrorists than they destroy.

His comments seem to be supported by videos released by Moscow's own defence ministry which appear to show cluster bombs from its fighter jets peppering large swathes of ground.

White House spokesman Josh Earnest also said Russia's airstrikes in Syria were 'indiscriminate' and risked prolonging the conflict 'indefinitely'.

He claimed Russia's 'random' strikes on Syria's enemies would draw the country deeper into the conflict.

Meanwhile, Turkey and its partners in the U.S.-led coalition against Islamic State called on Russia on Friday to cease its attacks on the Syrian opposition and focus on fighting Islamist militants, expressing 'deep concern' over Moscow's air strikes.

Grandure: Russian President Vladimir Putin (pictured at a meeting of the Presidential Council for Civil Society and Human Right) has denied that Russian warplanes have targeted civilians

Opulence in war: Putin addressed members of the Presidential Council for Civil Society and Human Rights (pictured) at the Kremlin in Moscow

In a joint statement with the United States, Britain, France, Germany and Gulf Arab allies, Turkey said Russia's actions constituted a 'further escalation' of the conflict and would only fuel more extremism.

'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 since yesterday which led to civilian casualties and did not target Daesh,' it said.

Daesh is another name for the Islamic State group.

Russia's decision to join the war with air strikes on behalf of Syrian President Bashar al-Assad this week, and the increased military involvement of Iran, could mark a turning point in a conflict that has drawn in most of the world's military powers.

Hundreds of Iranian troops have arrived in Syria to join a major ground offensive in support of Assad's government, Lebanese sources said on Thursday, a sign the civil war is turning still more regional and global in scope.

One of the sources said the Iranian ground forces were 'soldiers and officers', not advisers, adding: 'We mean hundreds with equipment and weapons. They will be followed by more.'

They are being supported by Russia's warplanes who bombed camps of rebel fighters trained by the CIA, one of the group's commanders claimed.