The BBC's Rosie Hayes: "Nkomo was the country's first modern nationalist leader"

Mr Mandela, who first met Mr Nkomo in the 1940s, described him as a comrade in the black liberation struggle.

"He was one of those freedom fighters who stood up for justice at the most difficult time in the course of our struggle," Mr Mandela said.

The announcement of Mr Nkomo's death was made on national radio by President Robert Mugabe, his one-time comrade in the fight against white minority rule in the former Rhodesia.

State radio and Ziana news agency reported that Mr Nkomo - who was a vice-president - died in the early hours of Thursday at the Parirenyatwa hospital in Harare.

He had been admitted several weeks ago suffering from prostate cancer.

President Mugabe described him as a "compatriot, a colleague and a comrade."

Mr Nkomo's body is to be taken to his home town of Bulawayo but will be returned to Harare for a funeral on Monday.

He will be buried at Heroes Acre - the national shrine to those who fought for Zimbawe's independence.

Founding father

President Mugabe:"A loss so keenly felt"

Mr Nkomo first made his mark during an era of great African nationalist leaders like Kwame Nkrumah of Ghana and Jomo Kenyatta of Kenya.

In the 1960s he was leader of Zapu, the Zimbabwe African People's Union, whose aim was the establishment of one-man-one-vote in what was then white-ruled Rhodesia.

He was joined by rival nationalist leader Robert Mugabe, of the Zimbabwe African National Union (Zanu), to found the Patriotic Front party in 1976 which heralded the end of colonial domination.

White rule persisted through a period of escalated guerrilla warfare conducted by the two leaders, but the conflict was finally resolved at the 1979 Lancaster House Conference in London.

The country's first free elections were held the following year, and Mr Mugabe was elected president.

Civil war

The two founding fathers of Zimbabwe's independence clashed during the early 1980s, leading to a bitter civil war and deep emnity between them.

This was only patched up in 1987 with Mr Nkomo's appointment as vice-president.

Political analysts say his death may renew tensions between his mainly Ndebele followers and Mugabe's largely Shona-dominated ZANU-PF.

Mr Nkomo's fortunes have deteriorated in the last 10 years since Robert Mugabe introduced the so-called Unity Accord, which created a one-party state in Zimbabwe.

Mr Nkomo has been in and out of hospital during the last year and in the last five years has received treatment in South Africa.