Russia's air force hit 27 "terrorist" targets in Syria overnight, the defence ministry said, as Moscow ramped up its campaign in the war-torn country. 

"Russian warplanes conducted 22 flights overnight. The crew of Sukhoi Su-34, Sukhoi Su-24M and Sukhoi Su-25 aircraft struck 27 terrorist targets on Syrian territory," the defence ministry said in a statement, adding it had hit Islamic State targets in the provinces of Hama, Raqa and Homs.