KHARTOUM (Reuters) - At least three people were killed and more than 20 wounded when Sudanese troops clashed at a South Darfur refugee camp with displaced people protesting against a visit by President Omar Al-Bashir, the United Nations mission said on Friday. The United Nations said clashes erupted when troops dispersed protesters as Bashir visited the Shatia area, where the government has been accused of ethnic cleansing, in his first trip there since the conflict in Darfur war broke out in 2003. Bashir traveled to Darfur to show progress before a U.S. decision in October on lifting sanctions in return for Sudan meeting conditions, including resolving conflicts and improving humanitarian efforts on the ground.  At least three displaced people were killed and 26 more wounded when troops cleared protesters at the Kalma camp, the joint U.N., African Union peacekeeping mission, known as UNAMID, said in a statement.  I call upon everyone involved in this situation to restore calm as soon as possible. A peaceful resolution of differences is the only way forward for the Darfuri people,  said UNAMID Joint Special Representative, Jeremiah Mamabolo. Sudan s government in South Darfur later said in a statement that two had died in clashes between displaced people at the camp opposed to Bashir s visit and those who supported him. It said some had opened fire on security forces. Conflict in Darfur began in 2003 when mainly non-Arab tribes took up arms against Sudan s Arab-led government. Fighting between the army and rebels in the southern Kordofan and Blue Nile regions also broke out again in 2011, when South Sudan declared independence. Short term truces have been announced last year. 