Feuding black political organizations in South Africa on Friday signed an agreement aimed at ending the country's bloodiest ongoing conflict, in which more than 600 people have died in 20 months. The fighting in Natal Province has pitted supporters of militant anti-apartheid organizations against members of Inkatha, a more conservative group headed by prominent Zulu leader Mangosuthu Buthelezi. The agreement condemns violence and calls for formation of a conciliation board that would review residents' complaints of harassment or attacks. Meanwhile, Nelson Mandela, the nationalist leader recuperating in an exclusive Cape Town clinic, has revisited his prison cell to pack his belongings.