Russian military action in Syria is increasing the number of refugees trying to reach Europe, European Council President Donald Tusk has said.

Speaking at a G20 summit in Turkey, Mr Tusk said Russia should focus more on Islamic State (IS) militants and not against "moderate Syrian opposition".

Russia has been carrying out air strikes it says target IS.

But many in the west fear the real aim is to keep Moscow's ally, Syrian President Bashar al-Assad, in power.

The G20 summit of world leaders is primarily focused on economic matters, but the two-day meeting in the coastal province of Antalya has been overshadowed by the deadly attacks in Paris.

IS said it was behind the series of assaults that left 129 dead, and Mr Tusk said cooperation between the US and Russia in their action against IS in Syria was "crucial".

'New wave of refugees'

"We need not only more cooperation, but also more good will, especially from Russian action on the ground in Syria," he said.

"It must be focused more on Islamic State and not, because we cannot accept it, against the moderate Syrian opposition."

He warned the Russian operations would "only result (in) a new wave of refugees. And we have some signals that in fact it's started.''