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 sorties overnight. The crews 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.

The ministry said it had destroyed eight Islamic State group strongholds near populated areas in the Homs province, and hit 11 training camps affiliated with the jihadist group in the Hama and Raqa provinces.

"As a result of the strikes, the infrastructure used for the training of terrorists has been destroyed," the statement said.

The Russian military also claimed it had struck underground hideouts used by militants near the villages of Salma and Arafit, located in the coastal Latakia province.

Moscow launched its bombing campaign in Syria last week, firing missiles from fighter jets and warships in the Caspian Sea, at targets it says belong to IS and other "terrorist" groups.  

The Syrian army says it has launched a "vast offensive" with Russian air cover, lending weight to fears from the US and its allies that Moscow's intervention aims mainly to bolster its long-standing ally President Bashar al-Assad.

Source: AFP