Russian planes back Assad's ground attacks
The Assad regime has launched a major ground offensive against rebel forces in western and central Syria, backed by a barrage of Russian cruise missiles and air strikes in the first co-ordinated assault by the allies.
Fighting raged heaviest in the regime-held province of Hama, where US-backed Free Syrian Army rebels destroyed several tanks and held their ground against strafing helicopters.
Some 1,000km away in the Caspian Sea, Russian warships sent dozens of cruise missiles to join the fray.
Russia's defence ministry said it had struck 11 Isil positions, while an official video appeared to show that it had hit rebel-held territory in Aleppo and Idlib.
The deployment of cruise missiles and air strikes marked a significant escalation of the campaign to shield the regime from rebel forces.
It was the first time that operations had been openly co-ordinated with forces loyal to Bashar al-Assad, one of the Kremlin's only remaining allies in the Middle East.
Vladimir Putin, the Russian president, said that air and ground offensives would be "synchronised".
Moscow has justified its military campaign as a move against Isil, but air strikes have focused on the belt around the Syrian regime's western heartland, hitting non-Isil groups and causing dozens of civilian casualties.
Ahmet Davutoglu, the Turkish prime minister, said yesterday that only two Russian air strikes had hit Isil territory to date, according to intelligence assessments.
It has also emerged that Russian fighter jets entered the flight path of US predator drones over Syria on at least three separate occasions last week.
It was the first use of cruise missiles by the Russians in Syria in a major escalation of its military operations, with 26 launched from four warships in the Caspian Sea.
The missiles, which would have had to fly 1,500km, over Iran and Iraq, were specifically targeted at Isil positions, destroying 11 of them, according to the Russian Defence Minister, Sergei Shoigu.
However, Syrian opposition and British and American officials said they would be monitoring what has happened on the ground to ascertain whether any 'moderate' rebel groups had been hit.
Submarine-launched Tomahawk missiles have long been a favoured choice of weapons of the US, but had not, hitherto, been a usual tool of war for Moscow.
According to the Russian and British military, the ships carrying out the attacks were the frigate Dagestan and corvettes Grad Sviyazhsk, Uglich and Veliky Ustyug.
The Russian defence ministry said that the flight paths of the missiles had been discussed with the "friendly states" - Iraq and Iran - to avoid urban areas.
It also claimed that the US was informed once the operation was under way.
Mr Shoigu said that 112 targets had been hit since Russia began air strikes. British military officials claim that only one in 20 targeted Isil.
Meanwhile, US President Barack Obama telephoned the president of Medecins Sans Frontieres (MSF) yesterday to apologise for the US bombing of a hospital in Afghanistan that left 22 people dead.
MSF has said that the air strike that levelled the hospital constituted a war crime and has demanded an independent investigation. The US has admitted that it mistakenly bombed the MSF facility, in the battleground city of Kunduz, last Saturday.
The White House said on Tuesday that additional information was needed before Mr Obama would issue an apology, but reversed course yesterday.
Josh Earnest, the US president's spokesman, said Mr Obama called Dr Joanne Liu, the network's international president, "to apologise and express his condolences for the MSF staff and patients who were killed and injured".
"The president assured Dr Liu that the department of defence investigation currently under way would provide a transparent, thorough and objective accounting of the facts and circumstances of the incident," Mr Earnest said.
Mr Obama's apology came a day after the US military commander in Afghanistan acknowledged American responsibility for the bombing.