The main insurgent group in the Syrian province of Idlib has pulled out of a key rebel town as government forces advanced in the area amid intense bombardment and air strikes, a militant group and opposition activists said.

As the militants withdrew, government troops moved into northern and western neighbourhoods of Khan Sheikhoun, marking a significant gain for President Bashar Assad’s forces as they try to chip away at territory controlled by the opposition in Idlib.

The northwestern province, dominated by an al Qaida-linked faction, is the last major rebel-held bastion in Syria.

Hayat Tahrir al-Sham, Syria’s main al Qaida-linked faction, said in a statement that its fighters carried out “a redeployment”, withdrawing to areas south of the town of Khan Sheikhoun. From there, they would continue to defend the territory, it said.

Syrian state TV said government troops have expanded their presence in the Khan Sheikhoun area, without giving further details.

“The victories that were achieved show the determination of the people and the army to strike terrorists, until all parts of Syria are liberated,” Mr Assad said, according to comments released by his office.

Bashar Assad, second right, meets a Russian delegation in Damascus
Bashar Assad, second right, meets a Russian delegation in Damascus (SANA via AP)

The withdrawal is a blow to the opposition. Syrian government forces have been on the offensive in Idlib and northern parts of Hama province since April 30, forcing nearly half a million people to flee to safer areas further north.

The fighting also killed more than 2,000 people, including hundreds of civilians.

After months of intense bombardment, the insurgents’ defences appear to be crumbling as they are losing ground at a much faster pace compared with the first three months of the government push.

In the long-running Syrian civil war, now in its ninth year, the north-western region — where Turkish, Russian, US and Iranian interests are at stake — has taken centre stage in the conflict.

The latest government gains come as Nato allies Turkey and the US discuss setting up a buffer zone inside Syria — one that Ankara wants to push Syrian Kurdish fighters it considers terrorists further to the east.

There has been speculation that Russia and Turkey, which back rival sides in Syria’s conflict, have reached an agreement that would allow the Syrian army to retake parts of Idlib and reopen a highway that links the capital Damascus with the northern city of Aleppo, Syria’s largest.

Khan Sheikhoun, held by militants since 2014, sits on that highway.

After the capture of Khan Sheikhoun, Syrian troops are likely to move north towards Maaret al-Numan, another town on the highway that has been subjected to intense air strikes over recent days. Opposition activists also reported intense bombardment on the rebel-held town of Jisr al-Shughour on the south-western edge of Idlib on Tuesday.

Backed by Russian air power, Syrian troops entered parts of Khan Sheikhoun overnight, according to opposition activists, and are clearing the area of explosives and booby traps.

“After fierce bombardment by the criminal enemy that avoids direct confrontation with holy warriors by implementing a scorched earth policy, our fighters have redeployed south of Khan Sheihoun,” the insurgents’ statement said.

The Britain-based Syrian Observatory for Human Rights, an opposition war monitor, said the al Qaida-linked Hayat Tahrir al-Sham and other insurgent groups withdrew from Khan Sheikhoun as well as the towns and villages south of the town.

According to the Observatory, Khan Sheikhoun was home to about a million people, nearly 700,000 of them displaced by fighting in other parts of the country, before the government offensive began in April. In recent days hundreds of civilians remained in the town, according to the group that tracks Syria’s war, now in its ninth year.