Syrian forces have retaken several villages in northwestern Syria, a monitor said Thursday, a move that could tee up an offensive against the last major militant bastion of Idlib.

More than six years into the deadly Syria conflict, Idlib province, which borders Turkey, is the only major region in the country still completely beyond government control.

Fierce clashes have in recent days pitted regime forces against Fateh al-Sham Front, a former Al-Qaeda affiliate, on the edge of the province, the Syrian Observatory for Human Rights said.

“The army took several villages,” the head of the Britain-based monitor, Rami Abdel Rahman, said.

He said the government push was backed by Russian airstrikes and added that the “regime wants to seize the southeast of Idlib province.”

The latest fighting took place in villages on the border between Idlib and Hama provinces where clashes have been ongoing for two months.

The government has had no presence in Idlib province since 2015.

Fateh al-Sham, previously known as Al-Nusra Front, crushed its former militant allies in the summer to become the dominant force there.

Idlib is one of four “de-escalation” zones in Syria covered by a deal meant to reduce violence levels that was struck in May by government backers Russia and Iran and rebel supporter Turkey.

More than 340,000 people have been killed and millions driven from their homes since Syria´s conflict erupted with anti-government protests in 2011.