khartoum least three people kill 20 wound sudanese troop clash south darfur refugee camp displace people protest visit president omar al-bashir unite nations mission say friday unite nations say clash erupt troop disperse protesters bashir visit shatia area government accuse ethnic cleanse first trip since conflict darfur war break 2003. bashir travel darfur show progress u.s. decision october lift sanction return sudan meet condition include resolve conflict improve humanitarian efforts grind least three displace people kill 26 wound troop clear protesters kalma camp joint u.n. african union peacekeeping mission know unamid say statement call upon everyone involve situation restore calm soon possible peaceful resolution differences way forward darfuri people say unamid joint special representative jeremiah mamabolo sudan government south darfur late say statement two die clash displace people camp oppose bashir visit support say open fire security force conflict darfur begin 2003 mainly non-arab tribes take arm sudan arab-led government fight army rebel southern kordofan blue nile regions also break 2011 south sudan declare independence short term truces announce last year three dead sudan clash bashir visit south darfur u.n