abidjan three unite nations soldier chad kill two others wound explosive device escort convoy northern mali thursday peacekeeping mission west african nation say 80 members un mission know minusma kill since 2013 attack militant group active country north center make world deadly peacekeeping operation mission say statement peacekeepers vehicle strike explosive device northern towns tessalit aguelhok around 2:30 p.m. 1430 gmt minusma spokesman olivier salgado late tell radio france internationale soldier involve chad one region effective armies condemn great energy abject act whose objective destabilize country harm peace process way mali say interim mission chief koen davidse rise jihadist group link al qaeda islamic state arid sahel alarm western power like france deploy thousands troop region response four u.s. special force troop kill early month neighbour niger fighters believe belong local islamic state affiliate operate mali militants exploit porous border particularly mali niger burkina faso step attack military civilian target include tourist sit regional capitals g5 sahel anti-terrorism taskforce soldier three countries well chad mauritania plan launch first joint operations come days explosion kill three chadian u.n. peacekeepers northern mali