US-led air raids have struck Syrian rebels not linked to the Islamic State of Iraq and the Levant (ISIL), expanding the coalitions raids for the second time to other groups fighting in Syria.

Activists in Syria told Al Jazeera the raids struck the Ahrar al-Sham rebel group in the northern province of Idlib, and the Syrian branch of al-Qaeda, the Nusra Front, in western Aleppo on Thursday.

At least six coalition air raids struck Idlib overnight, with one targeting an Ahrar al-Sham position in the village of Babska.

One of Syria's largest armed opposition groups, Ahrar al-Sham is a key member of the Islamic Front coalition, which seeks a state run on Islamic principles as its fights to topple Syrian President Bashar al-Assad.

Air raids also targeted the Nusra Front in the Reef al-Muhandisin area of western Aleppo, reportedly killing several of the groups' fighters as well as six civilians.

The Nusra Front, which has several bases in the area, confirmed the strikes on Twitter, saying the raids caused a high number of civilian casualties.

Al Jazeera could not independently confirm the number of casualties.

Meanwhile, Al Jazeera also learned that one of the air strikes killed David Drugeon, a French national, who is identified as a skilled bomb expert for Nusra. The strike targeted Drugeon while he was in his car in Sarmada near the Turkey-Syrian border.

The US and Arab states have been carrying out air strikes against ISIL in Syria since September 23, in a bid to prevent the armed group from seizing more territory in the conflict-hit nation.

Targeting Khorasan

On the first day of the attacks, the US-led coalition also hit a group of al-Qaeda veterans that the US administration called "Khorasan", although analysts said the attack actually targeted the Nusra Front.

There have been no reported attacks on groups outside ISIL since, but the latest air raids come after the group made gains against Western-backed rebel fighters in the Idlib region.

Nusra fighters in the past week drove the Syrian Revolutionary Front from its bastion in Idlib and captured a town after the withdrawal of the Hazm movement, another moderate opposition group.

The three-year war in Syria has killed an estimated 200,000 people and divided the country.

Rebel groups fighting the regime have taken over large swathes of land while ISIL holds territory in the north and east.

Nearly 10 million people have been displaced by Syria's civil war, and an estimated three million refugees have fled the country, according to the UN.