CAPE TOWN, South Africa (AP) _ A bomb blasted the roof off a bus shelter today about 330 yards from President P.W. Botha's house in the luxurious Groote Schuur Estate, police said. A young white woman was injured.

The bus stop is on a main road about 15 feet from the gate to the estate, where several Cabinet ministers live during Parliament sessions. The luxury residential complex is walled and heavily guarded.

The South African Press Association said the shelter was ''directly in front of'' the official home of Alwyn Schlebusch, minister for administration and broadcasting services in the state president's office.

Officers at the scene said they believed the blast was caused by a limpet mine.

The noon explosion blew the shelter's roof about 55 yards away, according to bystanders.

Keith Oliver, an advertising agency director, said he and four other men ran to the site to help the injured woman, who was taken by ambulance to a hospital.

Before today, 34 bombings had killed nine people and injured nearly 200 since a state of emergency was declared June 23. This was only the fourth to occur in Cape province. Most of the explosions have been in Transvaal province and Natal.

Censorship rules imposed under the state of emergency ban or restrict reporting about unrest, security force actions, treatment of detainees, most forms of peaceful protest and a broad range of statements the government considers subversive.

The government blames the outlawed African Nation Congress, the main guerrilla group fighting South Africa's government, for the bombings. ANC President Oliver Tambo said last week during a visit to the United States that it has a policy against direct attacks on civilian targets.

By law and custom, apartheid establishes a racially segregated society in which the 24 million blacks have no vote in national affairs. The 5 million whites control the economy and maintain separate districts, schools and health services.