Russian air strikes kill 14 civilians in eastern Syria as violence intensifies

Russian air strikes killed 14 people fleeing across a river on rafts in eastern Syria as renewed fighting across the country took an ever-mounting toll on civilians, a monitor said on Friday.

The strikes, the latest in a string of such incidents this week, targeted a group crossing the Euphrates near the extremist-held town of Mayadeen, the Syrian Observatory for Human Rights said.

"They were crossing the river on makeshift rafts in a village south of Mayadeen," Observatory director Rami Abdel Rahman said, adding that three children were among those killed overnight.

Russia has in recent days intensified its air raids in support of Syrian regime forces battling extremists across the country.

Abdel Rahman said the civilians were fleeing the village of Mahkan, south of Mayadeen, which lies about 420 kilometres east of Damascus and is one of the Islamic State group's main remaining bastions.

Mayadeen has been under IS control since 2014, when the group swept across swathes of Iraq and Syria and proclaimed a "caliphate", but regime forces have tightened the noose around the town.

The state news agency SANA said government forces advancing from desert areas northwest of Mayadeen had moved to within five kilometres of the town.

In Deir az-Zour province, IS still controls Mayadeen, eastern neighbourhoods of the city of Deir az-Zour further up the Euphrates Valley, the town of Albu Kamal downstream on the Iraqi border, and several other smaller towns.

Moscow has been carrying out relentless air strikes in support of its ally Damascus targeting both IS in Deir az-Zour province and rival extremists led by al-Qaeda's former Syria affiliate in Idlib province in the northwest.

Civilian deaths

The Islamic State group, which once controlled a territory roughly the size of Britain, has seen its "caliphate" shrink steadily over the past two years and has lost all but a few of its main hubs in both Iraq and Syria.

A Kurdish-led alliance is currently fighting IS in Raqqa, the group's biggest bastion since the recapture by Iraqi forces of Mosul in July.

The city, further up the Euphrates, was the de facto Syrian capital of IS's now collapsing "state".

On Wednesday, a Russian air strike killed 38 civilians trying to flee the fighting in Deir az-Zour province, according to the Observatory.

The Observatory relies on a network of sources inside Syria, and says it determines whose planes carry out raids according to type, location, flight patterns and munitions used.

The group has reported hundreds of civilians killed in operations against IS in Deir az-Zour and neighbouring Raqa province.

On Tuesday, it said a US-led coalition strike in Raqqa killed at least 18 civilians.

Russia has not acknowledged any civilian deaths from its strikes since it intervened in Syria in 2015, and dismisses the Observatory's reporting as biased.

On Thursday, the Red Cross said Syria was experiencing its worst levels of violence since the battle for second city Aleppo late last year.

"For the past two weeks, we have seen an increasingly worrying spike in military operations that correlates with high levels of civilian casualties," Marianne Gasser, the head of the International Committee of the Red Cross delegation in Syria, said.