The Russian military says it has not hit civilian targets in Syria since it first started its bombing campaign three months ago.

A senior Russian officer said Russian pilots were so well-trained they "never missed their targets".

It came after a report from Amnesty International earlier this week which claimed Russian airstrikes had killed hundreds of civilians - so many it could amount to a war crime.

The commander-in-chief of Russia's Aerospace Forces told the Rossiya 24 television channel: "The Military Space Forces have never hit civilian targets in Syria."

He added they have "never missed their targets, have never hit ... so-called sensitive places: schools, hospitals, mosques".

On Friday, Russia's defence ministry released footage of a strike on a convoy it says was smuggling oil across the Turkey-Syria border.

Philip Luther, director of the Middle East and North Africa Program at Amnesty International, had said: "Some Russian airstrikes appear to have directly attacked civilians or civilian objects by striking residential areas with no evident military target and even medical facilities, resulting in deaths and injuries to civilians. Such attacks may amount to war crimes."

Russian bombing began on 30 September prompting criticism from the US and the British Government, which accused Vladimir Putin of just acting to bolster Syrian president Bashar al-Assad.

In October UK defence secretary Michael Fallon said Ministry of Defence intelligence suggested only one in 20 Russian airstrikes were on targets to damage so-called Islamic State.

He said: "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."

However, Russia has insisted its campaign does focus on the terrorist organisation.

It comes after a new message was released apparently from the leader of so-called Islamic State in which he claimed bombing by Russia and the US-led coalition had only increased the group’s resolve.

In the 24-minute audio message, Abu Bakr al-Baghdadi said: "We promise you, God permitting, that whoever participates in the war against the Islamic State will pay the price dearly."

The audio message has not been independently verified but was posted on IS-affiliated websites and Twitter in the same way as previous IS messages.

Talks between Syria's warring parties are due to begin in Geneva at the end of January in an attempt to bring to an end nearly five years of civil war.