Three Cameroonian aid workers with a French NGO who were kidnapped in the country's jihadist-hit north were freed in Nigeria Friday after 100 days in captivity, their organisation told AFP.

The two men and a woman "were freed this evening near Maiduguri" in northeastern Nigeria, around 100 kilometres (62 miles) from the Cameroonian border, said Olivier Routeau, head of operations at Premiere Urgence Internationale (PUI).

"It is a little early to say they are in good health, but they are safe and sound, shaken, but we are reassured about their physical integrity," he added.

"They were smiling on the photos we were sent."

Routeau was unable to provide further details on the circumstances of the liberation or the group which held them, but said the Nigerian army had collected them.

All three were kidnapped on January 10 in the village of Yeme in Cameroon's Far North region, where they were working on food security and the fight against malnutrition, PUI said at the time.

Cameroon's northern tip and northeastern Nigeria have been the scene of violence involving the Boko Haram jihadist group and its bitter rivals, Islamic State West Africa Province.

The rebels frequently carry out killings and kidnap civilians for ransom. Other criminal groups also take civilians hostage and usually hand them back in exchange for money.

PUI has been based in Cameroon since 2008 and works to meet the health, food and educational needs of populations affected by armed attacks.

In March 2022, five employees of Doctors Without Borders (MSF) were freed in Nigeria after being kidnapped in Cameroon's Far North a month earlier.