Following days of contemplation by Russian PM, the 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.

Within hours of the decision, US officials said Russia appeared to have carried out its first attack.

Senior Kremlin official Sergey Ivanov said no ground troops would be involved in Syria, only 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 Adolf 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 air strikes 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. That was later confirmed in a statement from the Syrian president's office.

As Russia stepped up its involvement in Syria, reports said Syrian government planes had carried out attacks on three towns north of the city of Homs. At least 17 people were killed, including five children, activists said.