Unidentified gunmen have abducted 10 humanitarian aid workers as they were distributing food in a village in southwestern Niger, their NGO said in a statement.

She told the AFP news agency APIS, a partner of the UN World Food Programme, had worked in the volatile region near the borders with Burkina Faso and Mali "without problems" in the past year.

Gunmen in the area have previously stolen several vehicles of the International Committee of the Red Cross (ICRC) and Doctors Without Borders (Medecins Sans Frontieres, or MSF) in the region.

Fighters with links to al-Qaeda and the ISIL (ISIS) group have increasingly mounted attacks across the Sahel in recent years despite the presence of thousands of regional and foreign troops in the region.

The violence has hit Mali and Burkina Faso the hardest, rendering large swaths of those countries ungovernable, but it has also spilled into Niger, which shares long and porous borders with its two neighbours.