Russian jets carried out air strikes on areas in western Syria on Saturday and an Islamic State stronghold in the north was rocked by a large explosion, the Syrian Observatory for Human Rights monitoring group said.
Russia, a top ally of Syrian President Bashar al-Assad, started bombing in Syria on Sept. 30 saying it was targeting Islamic State militants, a campaign that has drawn Moscow deeper into Syria's more than four-year conflict.
Rebels on the ground and Western states have said Moscow's air campaign, which has been combined with ground attacks by pro-government forces, have mainly targeted rebel groups not associated with Islamic State, including U.S.-trained fighters.
Russian strikes hit northern areas of Latakia province, the coastal heartland of Assad's Alawite minority sect, as well as northern areas of Hama province further east, the Syrian Observatory for Human Rights said.