Damascus (AFP) - Syria's army Sunday seized a key town from the Islamic State group in the east of Aleppo province, a military source said, nearing its goal of expelling the jihadists from the region.

The capture of Maskana, on the western bank of Lake Assad, comes as part of a major Russian-backed military operation that began in mid-January to drive the jihadists from Aleppo province.

"Military units continue to advance in the east of Aleppo province and track down groups of Daesh terrorists," a military source cited by Syrian state media said, using the Arabic acronym for IS.

"Security and stability has been restored to the strategic town of Maskana and a number of areas," the source added.

Maskana was a key target for the Syrian army, and lies around 15 kilometres (10 miles) from neighbouring Raqa province, where the US-backed Syrian Democratic Forces are expected to soon launch an assault on the IS bastion of Raqa city.

Syria's army is not so far expected to play a role in that operation.

A military source told AFP the "Maskana area is the last important civilian population centre on the eastern border of Aleppo province before Raqa province".

"Whoever controls Maskana controls the axes running between Aleppo city and Raqa city," he added.

IS presence in the east of Aleppo province is now "at its end", he added.

The Syrian army has captured more than 200 towns and villages since it launched its operation in the east of Aleppo province, after retaking the provincial capital in December.

IS now holds just a handful of "scattered villages that can easily be captured in the east and southeast of Aleppo province, in desert areas," said Rami Abdel Rahman, director of the Syrian Observatory for Human Rights monitor.

More than 320,000 people have been killed in Syria since the conflict began in March 2011 with anti-government protests.