Clashes between regime loyalists and insurgents in rebel-held northwest Syria killed 59 combatants on Tuesday, a war monitor said.
Hayat Tahrir al-Sham, a jihadist group led by Syria’s former al-Qaeda affiliate, has since January controlled most of Idlib province as well as parts of neighbouring Hama, Aleppo and Latakia provinces.
Several other armed rebel groups also operate in the region.
Fighting in southern Idlib and rural Latakia on Tuesday claimed the lives of 29 pro-government forces as well as 30 jihadists and allied rebels, the Syrian Observatory for Human Rights said.
It came as airstrikes killed six civilians in southern Idlib, including three in the town of Khan Sheikhoun, the Britain-based monitor added.
Regime forces and anti-government fighters have been caught in fierce battles in the region for days, as the former presses with an advance toward a strip straddling the Hama and Idlib governorates.
On Sunday, regime forces seized the town of Al-Habeet in Idlib’s southern countryside, in their first major ground advance in the province since an escalation on the jihadist-dominated enclave more than three months ago.
The region was supposed to be protected from a massive government offensive by a Turkish-Russian buffer zone deal struck last September.
But it has come under increasing bombardment by Damascus and its backer Moscow since the end of April that has killed 816 civilians, according to the Observatory.
The violence has also pushed 400,000 people from their homes, according to the United Nations.
Syria’s conflict has killed a total of more than 370,000 people and displaced millions since it started with the brutal repression of anti-government protests in 2011.
Regime fighters pushed further into a jihadist-run bastion in northwest Syria Wednesday, inching towards a key town after months of deadly bombardment, a monitor said.
Eight years into Syria’s civil war, the jihadist-run region of Idlib is the last major stronghold of opposition to president Bashar al-Assad’s regime.
Air strikes and rocket fire by the regime and its ally Russia have pounded Idlib for more than three months, killing hundreds and displacing tens of thousands.
In the south of the stronghold, almost all residents of Khan Sheikhun — which lies on a key highway coveted by the regime — have left the town.
The road in question runs through Idlib, connecting government-held Damascus with the northern city of Aleppo, which was retaken by loyalists from rebels in December 2016.
After a week of ground advances, Assad’s fighters were just a few kilometres away from the town on Wednesday, the Syrian Observatory for Human Rights said.
‘Regime forces are now four kilometres from Khan Sheikhun to the west, with nothing between them and it but fields,’ Observatory chief Rami Abdel Rahman said.
To the east, pro-Assad fighters are battling to control a hill just six kilometres (less than four miles) from the town, the head of the Britain-based Observatory said.
Clashes on Wednesday have killed 14 regime forces, as well as 20 jihadists and seven allied rebels, he said.
State news agency SANA on Wednesday said army troops had taken several villages from the jihadists and rebels in the area west of Khan Sheikhun.
AFP correspondents have reported seeing dozens of families flee fighting over the past few days, heading north in trucks piled high with belongings.
A buffer zone deal brokered by Russia and Turkey last year was supposed to protect the Idlib region’s three million inhabitants from an all-out regime offensive, but it was never fully implemented.
An alliance led by fighters from Syria’s former al-Qaeda affiliate — Hayat Tahrir al-Sham — took over full control of the anti-Assad stronghold in May.
Regime and Russian air strikes and shelling since late April have killed almost 820 civilians, the Observatory says.
The United Nations says dozens of health centres as well as schools have been targeted.
Humanitarian workers have warned that any fully-blown ground attack on Idlib would cause one of the worst humanitarian disasters of Syria’s war.
The conflict has killed more than 370,000 people and displaced millions at home and abroad since starting with the brutal repression of anti-regime protests in 2011.
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