Four Cabinet ministers and a delegation of church leaders made separate tours of South Africa's riot-torn black townships today, and afterward offered widely differing views of what had caused the wave of violence this week that left 38 people dead and more than 300 injured.

Louis Le Grange, the minister of law and order, said at a news conference at a temporary police base near here that the tour -- by helicopter and armored personnel carrier -- had strengthened his earlier impression that "certain organizations and individuals" were behind the trouble.

Bishop Desmond Tutu, general secretary of the Council of Churches and a leading spokesman for black South Africans, said after a tour by his 30-member executive committee that they were satisfied the causes of the unrest lay in the government's policies of racial segregation, known as apartheid.

Another of the Cabinet ministers, Frederick W. de Klerk, praised the police for "performing marvelously" during the riots, but a statement issued by the church council expressed "shock and anger at the irresponsible and uncontrolled actions of some members of the police."

The unusual inspection tour was taken as a sign that the government has been alarmed and embarrassed by the violent outburst, which coincided with the inauguration of a new constitution that gives political rights to some nonwhites for the first time.

Black nationalists have opposed the new constitution as a sham reform, and the riots have lent weight to their argument that it can do nothing to lessen the alienation felt by the black majority.

The four Cabinet ministers -- Le Grange, De Klerk, who is minister of the interior, Defense Minister Magnus Malan and Education Minister Gerrit Viljoen -- spent three hours flying over the ravaged townships in a helicopter and driving through some of them in an armored personnel carrier.