Security police with an armed escort yesterday raided the home of Winnie Mandela, wife of the imprisoned black underground leader Nelson Mandela, in the remote country town of Brandfort to which she was banished six years ago.

The raid took place while two white liberal members of Parliament, Helen Suzman and Peter Soal, were visiting Mandela. The police charged Mandela with breaking her banning order, which prohibits her from being in the company of more than one other person at a time.

According to M. K. Malefane, a family friend who also was present during the raid, the police arrived at Mandela's three-room house in four cars escorted by two truckloads of armed policemen in uniform.

Malefane said security police spent three hours combing through Mandela's house. They took some documents, a poster and a bedspread and questioned Mandela about the items, Malefane said.

According to Suzman, the bedspread was in the black, green and yellow colors of the outlawed African National Congress.

The police, confirming the raid, issued a statement last night saying that the action was part of an investigation and that its results would be submitted to the attorney-general of Orange Free State Province for a decision on whether to charge Mandela under the security laws.

Mandela has been subjected to frequent police attention since her husband, who is leader of the African National Congress, was sentenced to life imprisonment 20 years ago for plotting the overthrow of white minority rule in South Africa. She has lived for all of that time under a series of banning orders, restricting her movements and preventing her from being in "gatherings" or from being quoted.

South African authorities appear to be clamping down against all persons connected with the African National Congress. The clampdown began with the military attack on congress refugees in the neighboring country of Lesotho last month, in which 42 persons were killed.