The South African government intensified its crackdown on the black labor movement today when it detained Piroshaw Camay, general secretary of the country's second biggest union federation, the Council of Unions of South Africa.

Security police also detained the first whites to be held during the current wave of racial unrest, when they took away student leader Kate Phillip, university lecturer Guy Berger and social worker John Campbell before dawn today.

This brought the number of people detained for being involved with organizing a protest strike by black workers last week to 13, most of them labor union leaders.

Camay's detention follows that of Chris Dlamini, president of the country's biggest labor organization, the Federation of South African Trade Unions, last Friday. The two major labor union alliances together have a membership of more than 300,000.

They and other union leaders have been detained under a security law which allows the police to hold them for interrogation and to keep them in solitary confinement indefinitely without charges and without access to their families or lawyers.

The crackdown against the labor movement prompted the country's three leading business organizations to issue a rare joint statement today warning that the government was endangering industrial relations by its action.

The Association of Chambers of Commerce, the Federated Chamber of Industries and the Afrikaanse Handelsinstituut warned that "the wave of detentions is exacerbating a very delicate labor situation."

Saying that the detentions were damaging relationships between white employers and their black workers, the business groups urged the government to meet with them and the labor unions.