The blacks of Uitenhage buried their dead today in what many believe was the biggest and most emotionally charged funeral ever held in South Africa.

As many as 50,000 singing, chanting people packed a soccer stadium in the battle-scarred black township of Kwanobuhle, which has been the scene of almost continuous racial unrest for the past three months, for funeral services for those who were cut down by police gunfire three weeks ago on the outskirts of Uitenhage.

The six-hour funeral was marked by many fiery speeches reflecting the growing anger of South Africa's voteless black majority, but Nobel laureate Desmond M. Tutu seized the opportunity to make an impassioned appeal for an end to black retaliatory violence, which increasingly is becoming a feature of the unrest.

Twenty-nine coffins were laid out on tables in front of the grandstand and draped with the green, yellow and black colors of the outlawed African National Congress. The official death toll in the shooting was 19, and authorities said the additional 10 were the bodies of people killed in other disturbances in the troubled eastern Cape Province.

Black residents here claim that the true death toll in the shooting was 43 and that the police are withholding 14 bodies to falsify the figures. Whatever the truth, the dispute illustrates the animosity and mutual mistrust between the black population and the white law enforcement authorities.

As with all funerals of victims of unrest, this one quickly turned into a massive political rally. Two weeks ago the government issued a proclamation banning most black gatherings in eastern Cape Province and other troubled regions of South Africa. Funerals are still permitted, however, and these have become highly politicized occasions.

Today's massive gathering was a strange mixture of genuine mourning and an outpouring of political passions, with just a touch of something not unlike a carnival spirit. There was much rhythmic dancing, singing and chanting of slogans. It was a bright, sunny day in the Southern Hemisphere autumn, and the field was covered with brightly colored beach umbrellas.

Banners were everywhere, mostly denouncing police violence, the segregationist system called apartheid and the administration of President Pieter W. Botha. Dislike of the Reagan administration and Britain's Conservative government also revealed itself. One banner with an original numismatic touch declared: "Botha, Reagan, Thatcher -- three sides of the same coin."

The funeral's political dimension was that of the African National Congress, support for which counts as treason. Apart from the ANC flag draped over the row of coffins, there were songs and chants in praise of congress leaders Nelson Mandela and Oliver Tambo and the underground organization's guerrilla wing, Umkhonto we Sizwe (Spear of the Nation).

A crowd of 3,000 was on its way to this township chanting these same slogans on the morning of March 21 -- the 25th anniversary of the Sharpeville massacre -- when police decided they were a threat to the nearby white city of Uitenhage and opened fire on them with semiautomatic rifles and shotguns.

Today the police kept in the background. Backed up by Army units with armored vehicles, they manned strategic points around the white city and an Air Force helicopter kept constant surveillance, but they made no attempt to confront the enormous crowd.

The effect on Uitenhage was eerie, as the blacks declared it a day of general mourning and stayed away from work -- which, given the apartheid pattern of residential segregation, meant they stayed out of the city. It left downtown Uitenhage looking deserted, with only occasional whites walking the streets.

With no labor force, many stores closed early, and at least one hotel apologized that it could serve no food, not even coffee and sandwiches.

The funeral service began and ended with great solemnity. With the big crowd hushed, a column of clergymen, led by Allan Boesak, a civil rights activist and president of the World Council of Reformed Churches, and a local Anglican minister, Mxolisi Daba, threaded its way through the crowd.

Behind them came the 29 coffins, headed by a young girl in a white veil carrying a plain white wooden cross. She was carried on the shoulders of black men representing activist organizations who walked silently with their fists raised in the black power salute.

Afterward, the coffins again were carried shoulder-high through the township streets to the cemetery, forming a bobbing column nearly 200 yards long between the dense crowd lining the route.

Many of the speeches rang with accusations against the Botha government and its police force, with frequent references to testimony given at the judicial inquiry into the shooting, where police have testified that the issue of tear gas and rubber bullets to Uitenhage riot squads was stopped March 15.

After that the patrols were issued only with semiautomatic rifles and shotguns with heavy cartridges. They also received an order to "eliminate" any rioter seen throwing gasoline or acid bombs.

There has been some acrimony between police witnesses at the inquiry, as senior officers have tried to shift the blame to one another. Last week the Uitenhage station commander, Maj. Gert Kuhn, accused his divisional commissioner, Col. Frederik Pretorius, of telling a "blatant lie" when he denied ordering that no more tear gas be issued.

"This massacre was no accident," said Fikile Kobese, a local trade union leader who acted as a kind of master of ceremonies at today's funeral. "It wasn't just a few policemen acting in a panic. They planned to kill our people. That is why they took no rubber bullets or tear gas with them."

Boesak likewise said the shooting was no accident, although he did not make the same accusation of calculated killing. It was, he said, "the inevitable result of a deliberate policy of greed, racism and domination" and "a systematic disregard for human rights and human life."

Boesak added: "We do not want to be vengeful, but it will not be easy to forget the horrors that have been inflicted on our people. The white rulers of this land should read their Bibles, and they will see there that as they sow, so shall they reap."

Speaking last, Tutu, whom most whites continue to regard as a radical extremist, was the voice of realism and moderation, warning blacks to prepare for a long and painful struggle, and urging them to avoid the retaliatory violence that increasingly has become a feature of the unrest, with a number of brutal killings of blacks seen as collaborators with the apartheid system.

Saying that he opposed the violence of apartheid and the use of violence to try to overthrow it, Tutu pleaded: "Don't undermine our wonderful cause. Let us not use the methods that are used against us by our enemies. When we finally achieve our goal of freedom, we must be able to look back with pride at how we got there."