French and Algerian fighters, some arriving from Syria, have joined the ranks of the Islamic State group in northern Afghanistan where the militants have established new bases, multiple international and Afghan sources have told AFP.

It is the first time that the presence of French IS fighters has been recorded in Afghanistan, and comes as analysts suggested foreigners may be heading for the war-torn country after being driven from Syria and Iraq.

It is also a troubling sign as France, which has faced the worst of the IS-inspired violence in Europe since 2015, debates how to handle hundreds of its citizens who went to fight for the group in the Middle East.

"A number" of Algerian and French nationals entered the largely IS-controlled district of Darzab in northern Jowzjan province in November, said district governor Baaz Mohammad Dawar.

At least two women were among the arrivals, who were travelling with a translator from Tajikistan as well as Chechens and Uzbeks, Dawar added.

Several European services believe the fighters are arriving through Tajikistan, the source said, adding that at least one Frenchman arrested there in July said he had wanted to join IS in Afghanistan.

European and Afghan security sources in Kabul confirmed Dawar's claim that French citizens were among the fighters -- though, one cautioned, "we do not know how many there are".

Three of the Algerians seen in Darzab are believed to have been in Syria and Iraq, Dawar said, suggesting they may link Islamic State-Khorasan Province (IS-K), the group's franchise in Afghanistan and Pakistan, with the main group in the Middle East.

When it first emerged in 2015, IS-K overran large parts of eastern Nangarhar and Kunar provinces, though initially its part in the Afghan conflict was overshadowed by the Taliban.

Afghanistan has long attracted foreign fighters, from the mujahedeen during the 1980s war against Soviet invaders to al-Qaeda's later use of the country as a haven.

The Pentagon has said IS numbers fewer than 1,000 in Afghanistan.