Syrian troops shelled the south of Idlib on Sunday, according to rescuers and residents in the rebel stronghold where a ceasefire had halted a fierce army offensive two weeks ago.

At least 40 militant leaders were killed Saturday after a missile attack targeted their meeting in northwestern Syria, hours after a Russian-backed ceasefire came into effect, a war monitor said.

Air strikes on Syria's northwestern Idlib region stopped on Saturday after a Russian-backed ceasefire went into effect following four months of deadly bombardment, a war monitor said.

Syria and its ally Russia have stepped up an offensive against the last big stronghold of Syrian rebels, mounting more air raids and deploying ground reinforcements including Iranian-backed militias

Air strikes hit rebel positions near a Turkish military post in northwest Syria on Wednesday, where the Russia-backed army has waged a fierce offensive against rebels

The leaders of Russia and Turkey said Tuesday they shared deep concerns over fighting in northwestern Syria

A car bomb exploded in the rebel-held Syrian city of Idlib on Saturday, a war monitor and opposition news channel said, as air strikes hit its outskirts in a government offensive on the last major opposition bastion.

Syrian troops on Friday reclaimed a cluster of towns they had lost early in the eight-year-old war, pressing their offensive in the northwest, the country's last big rebel stronghold.

More than 70,000 people were displaced from the southern countryside of Idlib province in Syria during August due to a surge in violence, Idlib's health directorate said on Wednesday.

Syrian rebels withdrew from a town in southern Idlib province and from their last remaining territory in neighbouring Hama province after government troops advances in the area

Militants on Wednesday downed a regime plane flying over northwest Syria as it took part in a deadly military campaign against the region and took the pilot prisoner

Regime loyalists captured a town and a village from militants and allied rebels in northwest Syria Wednesday, after fierce clashes that killed nearly 30 combatants overnight, a war monitor said.