South Africa's first post-apartheid Foreign Affairs Minister, Alfred Nzo, has died aged 74.

Mr Nzo suffered a stroke in the middle of December, and died on Thursday at a clinic in Johannesburg.

During the apartheid era, Mr Nzo served as secretary-general of the African National Congress in exile from 1969 to 1991.

Current ANC secretary-general Kgalema Motlanthe said he had learned of Mr Nzo's death "with a deep sense of loss and sadness".

He described Mr Nzo as "one of those few comrades who epitomised the noblest attributes of the ANC".

Defiance campaign

Alfred Nzo was born in Benoni near Johannesburg, and received his elementary missionary education in the Eastern Cape before entering Fort Hare University in 1945.

At Fort Hare, he joined the ANC Youth League and became active in student politics.

Mr Nzo became a health inspector and helped to organise the defiance campaign against apartheid in the 1950s.

In 1957 he organised the Alexandra bus boycott when the people of Alexandra township walked 15km (nine miles) to central Johannesburg and back every day for three months, to protest against the increase in bus fares.

Their demands were finally met.

Foreign envoy

Mr Nzo was placed under 24-hour house arrest in 1962 and detained for seven months the following year.

He joined the ANC in exile in 1964 and was elected the party's secretary-general in 1969 - a position he held until 1991.

He represented the ANC in countries including Egypt, India, Zambia and Tanzania.

He became foreign affairs minister under Nelson Mandela's presidency after the historic all-race democratic elections in 1994.

But as foreign minister he was criticised by the media for not taking a sufficiently pro-active role in the development of South African foreign policy, at a time when the country was transforming itself from apartheid pariah into an important regional power.

He retired from politics last year, when the ANC was re-elected under the leadership of Thabo Mbeki.