The operation in northwest Syria was the Islamist-led government's first known assault targeting jihadists since the ouster in December of longtime ruler Bashar al-Assad.

Since taking power, Syria's new leaders have sought to break from their own radical Islamist past and present a moderate image more tolerable to ordinary Syrians and foreign powers.

The group of foreign jihadists targeted by government forces on Wednesday is known as Firqatul Ghuraba in Arabic, or the Foreigners' Brigade, led by 50-year-old Oumar Diaby, a Franco-Senegalese criminal-turned-preacher who adopted the name Omar Omsen.

General Ghassan Bakir, a top Syrian security commander in the northwestern province of Idlib, said in a statement that government forces had completely surrounded the camp near the Turkish border, where Diaby is holed up.

The operation followed accusations that the group had kidnapped a girl.

Security forces "sought to negotiate with the leader to voluntarily surrender to the relevant authorities, but he refused and barricaded himself inside the camp... and began firing, provoking security personnel, and terrorising residents", Bakir said.

A monitoring group that has documented violence in Syria since the start of the country's civil war in 2011 also reported the operation.

Security forces launched a "large-scale operation" after encircling the camp "with the aim of handing over French members wanted by their government", said Rami Abdul Rahman, head of the Syrian Observatory for Human Rights monitor.

Diaby's son Jibril, a footballer in Idlib, told AFP via WhatsApp that "the clashes began after midnight and are still ongoing", adding that "security forces shelled the camp, which houses women and children".

Jibril also said that the clashes were linked to "France's wish to secure the extradition of two French members of the group".

An AFP correspondent on the ground said that violence had died down by early afternoon on Wednesday.

He was able to enter the camp, where he saw French fighters, as well as other foreign nationals.

The Observatory later confirmed that clashes had stopped, as "foreign (non-French) jihadists are mediating" to achieve a peaceful outcome.

- Balancing act -

In September 2016, the United States designated Diaby, suspected of funnelling French-speaking fighters to Syria, as an "international terrorist".

He is also wanted on a French arrest warrant.

The issue of foreign fighters who flocked to Syria during the years of conflict is a thorny one, with some countries refusing to take fighters back.

Interim President Ahmed al-Sharaa, who once led Al-Qaeda's branch in Syria, has played a delicate balancing act between presenting a moderate image to the world, and ensuring he does not antagonise the jihadists still in the country.

French security sources have previously told AFP that "around 50" people are believed to be part of Diaby's group.

The militants have no known relation to the Islamic State group, which was crushed in a US-led battle waged in alliance with Kurdish-led forces.

A resident of the Harem region, where the camp is located near the Turkish border, told AFP he had seen government forces bringing reinforcements to the area beginning Tuesday and had heard explosions.