The African National Congress, from its exile headquarters here, claims responsibility for the growing violence of the black revolt in South Africa. "This is a direct response to our organization," said Oliver Tambo, its president. "People are responding to the call of the ANC."

But many black leaders in South African townships, along with diplomats here and knowledgeable ANC sources say the congress is struggling to catch up with a home-grown revolution that it is not equipped to direct, arm or restrain.

"This is not an ANC-orchestrated revolution," said a senior western diplomat here, echoing a widespread consensus among black community leaders interviewed recently in South African townships. "In terms of control and strategic planning, I think Tambo would be less than honest to say that the ANC had arranged things."

"The revolutionary organization in Lusaka has been left far behind, but the leaders will never admit it," said a congress member.

Among blacks in South Africa, the ANC and its leaders, especially Nelson Mandela, remain the preeminent symbols of the struggle against apartheid. Mourners at the funerals of protesters killed by South African authorities carry signs about Tambo, the imprisoned Mandela and ANC liberation.

Public opinion polls among South African blacks have consistently shown Mandela to be their leader of choice. After 23 years in prison, he has assumed mythic importance to many young people who have neither seen him nor heard his voice.

Observers inside South Africa and in Lusaka say, however, that there is little evidence that the congress has been successful during last year's escalation of violence in converting its symbolic importance into military and political direction inside the country.

The ANC, as it has been for decades, continues to be infiltrated by South African intelligence agents, say diplomats and an ANC source. This creates severe difficulties in communication between the headquarters here and its underground operatives in South Africa.

For their own safety, many of these operatives reportedly choose not to use ANC channels in sending information out of the country. As a result, leaders in Lusaka are out of touch, the sources said.

The ANC also has not had significant success smuggling the quantity of weapons into South Africa that would be necessary to arm what it now terms the "people's war."

The leadership has said it is moving to supply grenades to the growing number of the blacks in South Africa who are willing to throw them. There have been no reports, however, of a sharp increase in such attacks on the ground.

Government authorities in mid-July seized a large ANC cache of mostly Soviet-made weapons in neighboring Swaziland. The ANC, in tacit acknowledgement of its inability to move weapons into South Africa, recently has urged protesters to steal guns and explosives.

"There are two separate and distinct situations for the ANC, one inside South Africa, one outside," said a member. "It has been far more successful working on the outside."

The ANC, as the oldest and most visible exiled opponent of apartheid, has developed in the past two decades into a sprawling, bureaucratic international organization, with offices in 21 countries besides Zambia.

It has gained recognition from governments of Sweden, the Netherlands, Norway, Finland and Ireland as the representative of the people of South Africa. It doles out scores of scholarships each year, using funds from governments and individuals, and runs a large education center in Tanzania. The center in 1982 had a budget of $5.5 million.

Thabo Mbeki, a member of the ruling council, said the organization's cash flow is "quite significant." Although the annual budget is secret, Mbeki said Scandinavian countries contribute $20 million a year for "humanitarian" purposes. The Soviet Union, ANC oficials said, is the primary supplier of weapons.

"The ANC is fat with conscience money from northern Europe," an ANC member in Europe said recently. "It is expert at tapping the conscience of the world."

Over the past 25 years, the ANC has been led by a generation of mostly middle-class blacks now in their fifties and sixties. Sometimes called "gentlemen bureaucrat revolutionaries," they have been criticized by younger members as having lost touch with the harshness of life in South Africa.

"There is no doubt that the ANC leadership has grown a bit fat from all the Swedish donations and hotel food," said a western diplomat here. "You cannot spend 20 years in exile and not be seduced by a softer way of life."

A younger generation, the "Soweto generation" that fled South Africa after violence erupted there in 1976, has pressed the older leaders in recent years to approve a more radical agenda, diplomats here say.

Perhaps the most radical part of that new agenda was adopted in a recent secret meeting in Zambia of ANC leaders. Spokesmen said a decision was made to strike at military personnel rather than to confine bombing attacks to such targets as oil refineries.

Mbeki, in explaining the new strategy, said the congress had decided it no longer needed the publicity impact of bombings such as an attack in 1980 on the Sasol oil-from-coal plant or the 1983 bombing in Pretoria of a South African military intelligence center -- in which 18 pedestrians were killed.

"We don't need those now," Mbeki said. "We went through a necessary phase of armed propaganda. We are to go over now to another phase of people's war." In that phase, he said, the ANC will supply and help train large numbers of people to use "very primitive means" -- such as gasoline bombs and hand grenades -- in attacks that will move increasingly into white areas of South Africa.

While the leadership reportedly agreed unanimously to pursue "people's war" as opposed to selective strikes by guerrillas, observers here and in South Africa continue to look for evidence that the ANC has the capability to execute it new strategy.