Russia launches cruise missiles at Isis Raqqa stronghold in Syria

Vladimir Putin has pledged to escalate his military campaign in Syria after it was confirmed that a bomb brought down a Russian airliner over Sinai

Russian President Vladimir Putin chairs a meeting on the results of the investigation of Russian MetroJet Airbus A321 crash in Sinai, at the Kremlin in Moscow, Russia, 17 November 2015 (EPA)

The Russian military has fired multiple cruise missiles at the Isis stronghold of Raqqa, the Kremlin has confirmed.

Russia's defence minister told a briefing with President Vladimir Putin that cruise missiles targeted militant positions across Syria's Aleppo and Idlib provinces.

Sergei Shoigu said the missiles were launched from Tu-160 and Tu-95 warplanes, and said they were among 2,300 sorties carried out by the Russian military in the past 48 days.

Earlier, US officials were quoted by the Reuters news agency as saying Russia had launched a "significant number" of strikes in Syria using both sea-launched cruise missiles and long-range bombers.

The French daily Le Monde cited senior French government officials as saying Russian missiles had struck Isis positions in Raqqa, its de facto capital in its Syrian territories.

According to reports, Russian officials gave their US counterparts notice ahead of the strikes, in a sign of closer cooperation between the two states after talks between Vladimir Putin and Barack Obama at the G20 summit.

Videos showing alleged cruise missiles flying and crashed in Syria appeared across social media on Tuesday, though their provenance could not be immediately verified.

Russia has vowed to escalate its military campaign in Syria after it was confirmed the airliner which crashed in Sinai was brought down by a bomb.

"Our military work in Syria must not only continue," Mr Putin said. "It must be strengthened in such a way so that the terrorists will understand that retribution is inevitable."

Speaking to the Associated Press, an unnamed US defence official said the Russian military had communicated prior to the attacks with the US-led coalition's centre of operations at the al-Udeid air base in Qatar.

Russia has been launching air strikes on Isis in Syria since the end of September, although it has faced accusations of targeting moderate Syrian rebels in a bid to support regime forces.