A 26-year-old French photojournalist has been killed in the Central African Republic while covering the sectarian conflict in the region.

Camille Lepage has been on assignment in the country for the past few months, and sold her pictures to major French and American newspapers.

She had been travelling in a village near the Camerounian border, when she was assumed to have been caught in cross-fire.

"She was probably ambushed," French President Francois Hollande told reporters. "We must do everything to find out why she was in this region, who captured her, how she died and make sure that her murderers do not go unpunished."

In her last post on Instagram on 6 May, Lepage said she was travelling with anti-balaka outfit patrolling the country while avoiding the African peacekeeping force.

"We left at 3:30 a.m. to avoid the Misca (African peacekeeping) checkpoints and it took us 8 hours by motorbike as there is no proper roads to reach the village," she wrote in the photo caption on Instagram.

"In the region of Amada Gaza, 150 people were killed by the Seleka between March and now. Another attack took place on Sunday killing 6 people, the anti-Balaka Colonel Rock decides to send his elements there to patrol around and take people who fled to the bush back to their homes."

Lepage's body was found by French peacekeeping force, who stopped the car driven by Christian "anti-balaka" fighters, about 60 kilometres from the western town of Bouar.

An aid worker deployed in the region told Reuters that the Christian militia was attacked by Fulani herdsmen, in the ongoing tit-for-tat violence between the two groups.

A statement from Hollande's office said that the President had requested an "immediate despatch of a French team and police from the African force deployed in the CAR to the scene".

Lepage was a freelance photojournalist and had worked with Reuters, New York Times and BBC among many other leading English publications. She had also worked for French newspapers including Le Monde and Liberation.

In an interview with photography website PetaPixel, Lepage expressed her strong views on covering stories from troubled regions of the world.

"I can't accept that people's tragedies are silenced simply because no one can make money out of them," she said. "I decided to do it myself, and bring some light to them no matter what."

Lepage was recently selected for a prestigious portfolio review and workshop at the New York Times.