BEIRUT — Syrian troops and allied militia backed by Russian airstrikes and cruise missiles fired from warships attacked rebel forces on Thursday as the government extended a major offensive to recapture territory in the west of the country.
Rebel advances in western Syria earlier this year had threatened the coastal region vital to President Bashar Assad's control of the area and prompted Russia's intervention on their ally's side last week.
In a further show of force, the Russian defense ministry said missiles fired from its ships in the Caspian Sea hit weapons factories, arms dumps, command centers and training camps supporting ISIS forces.
Ground forces loyal to the government targeted insurgents in the Ghab Plain area of western Syria, with heavy barrages of surface-to-surface missiles as Russian warplanes bombed from above, according to the British-based Syrian Observatory for Human Rights and a rebel fighting there.
It said rebels had shot down a helicopter in Hama province in western Syria. It was unclear if it was Syrian or Russian.
Syria said it had set in train a major military operation in a war that began more than four years ago as an attempt to unseat Assad through street protests and has now killed 250,000 people, sent millions into exile as refugees, and drawn in armed forces from world and regional powers.
Assad's armed forces "have launched wide-ranging attacks to deal with the terrorist groups, and to liberate the areas which had suffered from the terrorist rule and crimes," Syria's army Chief of Staff, Lt. Gen. Ali Abdullah Ayoub, was quoted as saying by state media.
Ayoub did not say which areas were being targeted. He said new fighting units, including one called the Fourth Assault Corps, had been set up to wage the campaign and the army now held the military initiative.
Wednesday's operation in Hama appeared to be the first major assault coordinated between Syrian troops and militia on the ground, and Russian warplanes and naval ships.
Russia says it is fighting ISIS. But while the group has been the target of some of its airstrikes, it has no foothold in the areas of western Syria targeted in the attacks on Wednesday and Thursday.