An expansion of the campaign, which has so far focused only on the enclave of Afrin, could drag Ankara into direct confrontation with US forces and their main Kurdish partners in Syria - the Syrian Democratic Forces (SDF).
In fighting that lasted 24 hours, the ultra-hardline militant group killed 36 Syrian soldiers, the British-based Syrian Observatory for Human Rights said.
Moscow has said it is helping Syria's government "finish off" fighters in Ghouta but has denied carrying out air strikes against civilians.
The total number of civilians, mostly children, who have been evacuated from Eastern Ghouta since the start of the humanitarian operation has risen to 79,702, Russian defence ministry said on Tuesday.
Over the past few weeks, Syria and Russian Federation have cornered foreign-backed militants in Eastern Ghouta, a suburb of Damascus, as part of their campaign to liberate civilians holed up there and end militant attacks from the suburb on the capital. Activists in the area said hundreds of civilians were arrested as they attempted to leave the area, adding that air raids on Monday killed at least eight civilians.
The clashes come after ISIS militants drove out pro-government forces from parts of the neighborhood that rebels abandoned last week as part of an evacuation deal with the Syrian government.
/ AFP PHOTO / Hamza Al-AjwehHAMZA AL-AJWEH/AFP/Getty Images Member of the Syrian Civil Defense group carries a boy who was wounded during airstrikes and shelling by Syrian government forces, in Ghouta, a suburb of Damascus, Syria.