Jihadists in northwestern Syria on Thursday launched an attack on government forces killing at least 11 fighters, a war monitor said, following a series of regime advances in the area.

The deadly assault in a northern strip of Hama province, comes amid an escalation in violence in parts of the country's northwest held by Syria's former Al-Qaeda affiliate Hayat Tahrir al-Sham (HTS).

Damascus and its ally Russia have since late April ramped up deadly air strikes and rocket fire on the region, and fighters have clashed on its edges.

Thursday's attack by HTS militants and allied jihadist groups in the village of Jibeen, follow a series of regime advances in the region in recent weeks, the Syrian Observatory for Human Rights war monitor said.

"The insurgents are launching a counterattack," Observatory head Rami Abdul Rahman told AFP.

He said at least five jihadists were killed in ensuing clashes.

State news agency SANA said that militants launched rocket attacks on a number of villages in northern Hama, destroying homes.

Syrian state television said that Syrian troops thwarted the assault on the villages of Tal Maleh and Jibeen.

Meanwhile, regime air strikes pounded the neighbouring province of Idlib and nearby areas on Thursday, as battles raged, the Britain-based Observatory said.

One civilian was killed in the bombardment, according to the monitor.

More than 300 people have been killed by regime air strikes and shelling in the area since late April, according to the Observatory.

The bombardment has also displaced nearly 270,000 people in May alone, according to the UN.

A total of 24 health facilities and 35 schools have been hit in the latest escalation, according to the UN's humanitarian office.

Analysts predict that Syrian President Bashar al-Assad and his allies will continue to chip away at the area, but not unleash a major assault that would create chaos on Turkey's doorstep.

The conflict in Syria has killed more than 370,000 people since it started in 2011.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)