Russia's upper house of parliament has voted to allow the military to be deployed in Syria, paving the way for air strikes on the militant Islamic State (IS) group.

The vote followed a request from Syria for military aid, senior Kremlin official Sergey Ivanov said.

Mr Ivanov ruled out the use of ground troops and said the step involved only the use of the air force.

President Vladimir Putin called this week for a broad anti-terror coalition.

He told the UN it should be similar to the alliance that opposed Hitler in World War Two.

A US-led coalition has been carrying out air strikes against IS in Syria and Iraq for more than a year.

But Mr Ivanov, the president's chief-of-staff, said US and French airstrikes in Syria circumvented international law, since they had not been authorised by a UN resolution or by the Syrian government.

President Bashar al-Assad, he said, had officially requested military assistance from Moscow.