Bamako - Four Malian Red Cross employees have been kidnapped in the country's restive centre, the organisation said on Monday, while a local official said negotiations were underway for their release.The Red Cross briefly suspended operations in the northern city of Kidal following a burglary at its offices last month, and has suffered kidnappings of its staff in the past by jihadist groups."Colleagues of the International Committee of the Red Cross (ICRC) and Red Cross Mali were kidnapped in the Tenekou area, Mopti region, on Sunday May 14 around 19:00," a Red Cross Facebook post said."They were conducting a survey of the humanitarian situation when unidentified and armed individuals said they had to come with them," it added.A local official in the rural community where the Red Cross staff were captured described the kidnappers as "Islamists" to AFP, adding that "negotiations were under way for their release".In April 2016, three Red Cross workers were taken hostage by Islamist group Ansar Dine in northeastern Mali, but were released days later.A Malian military source confirmed to AFP that the army had sent troops to participate in the search for the workers."We are very worried for our colleagues. We are doing everything possible to work out what happened and to ensure their safe release without precondition and as quickly as possible," said Jean-Nicolas Marti, the head of the ICRC delegation.Northern Mali fell to jihadist groups linked to Al-Qaeda in March 2012, and although these forces were driven out of key towns by a French-led military intervention the following year, the Islamists have now spread further south.Three Malian jihadist groups with previous Al-Qaeda links recently joined forces to create the "Group to Support Islam and Muslims" (GSIM), led by Iyad Ag Ghaly of Ansar Dine, and have claimed several attacks against foreign and domestic forces.