Helicopters from Operation Barkhane, France's anti-terrorist operation in Africa's Sahel and Sahara, were sent to Boulikessi following an attack from suspected jihadists on 5 March PHILIPPE DESMAZES/AFP/Getty Images

Four Malians who were working for the parish where Colombian nun Sister Gloria Cecilia Narváez Argoti was kidnapped last month have been charged over her abduction.

Colombian and Malian police mobilised to find the Mary Immaculate nun, who was abducted from her community on 7 February. She is believed to be in the hands of four armed men claiming to be Islamic militants who stormed the home where she served in Karangasso, southern Mali.

Four Malian nationals were charged with the kidnapping on 3 April and appeared in front of the judicial authorities specialised in the fight against terrorism in the Bamako capital, according to reports.

Among the suspects – who were charged with criminal association, unlawful possession of weapons and terrorism-related kidnapping – are workers from the parish where the nun was abducted.

Two of the suspects were drivers from the Karangasso parish. According to RFI, the drivers usually take turns driving the ambulance of the church. It was aboard this vehicle that Sister Gloria was taken after her abduction by the armed men.

Another suspect held in pre-trial detention is a cook who prepared food for the Catholic community of Karangasso.

Al-Qaeda-linked groups have recently been moving into previously untouched parts of Africa, as Islamist terrorists seek to gain exposure in the Sahel and neighbouring Burkina Faso, with which Mali shares a porous border.

Five years ago, al-Qaeda seized power in Mali's second city Timbuktu after hijacking an ethnic Tuareg rebellion in the country's Saharan north. They grabbed large swathes of land and threatened the capital, Bamako.

France's 2013 military intervention and UN peacekeeping missions have since returned control of the region to the Malian government, but authorities have subsequently intensified their military offensive against Islamist groups, which continue to operate across the vast desert areas.