Former civil rights militant Stokely Carmichael led a demonstration through the streets of Washington yesterday that attracted more than 3,000 people, including former Black Panther Bobby Seale, supporters of the Palestine Liberation Organization and persons who said they were Irish Republican Army sympathizers.

In the demonstration, which at times stretched over three city blocks, there were banners saying "All African People Unite" and signs that read, "Long Live the PLO!"

As Carmichael, former leader of the Student Nonviolent Coordinating Committee, led the group past the South African embassy to Meridian Hill Park, the predominantly young, black demonstrators chanted repeatedly:

"South Africa and Israel must be destroyed."

"We share the same enemies," said Lamin Jangha, one of the organizers of the All African People's Revolutionary Party demonstration in explaining why his group had joined with Palestine Liberation Day marchers from the Organization of Arab Students.

"The Palestinians are fighting against Zionism and capitalism," he said. "Zionism is racism and we too are fighting racism. The same enemies that have taken the land from the Palestinians are the enemies that are keeping Africa from the African people . . . it is closely linked to apartheid in South Africa."

Mohammad Sirhan of the Organization of Arab Students said the two groups had massed together as "a show of unity. We are fighting the same struggle against racism and liberation from the forces of colonialism and U.S. imperialism."

The Arab student's group had marched from the White House past the Israeli Embasy before joining the All African People's Revolutionary Party march at the statue of Taras Shevchenko, a Ukrainian poet and freedom fighter, at 22nd and P streets NW.

One of the five-member contingent of Irish Republican Army sympathizers, who would not identify himself, said his group had joined the march to show support "for all freedom fighters."

After the three-hour march ended at 2 p.m. the demonstrators went into Meridian Hill Park where a crowd estimated at 2,500 people by U.S. Park Police joined them to hear speakers from several organizations.

Bob Brown, an organizer with the All African People's Revolutionary Party, told the crowd at the park that yesterday's march was the 15th annual African Liberation Day demonstration, and coincided with the 31st annual Palestine Liberation Day.

"I want to thank the Palestinians, Arab students, for marching with us today," Brown said to the crowd as the smells of exotic foods, incense and marijuana wafted through the park. "We are together in the struggler against Israel and Rhodesia, Zionism and racism and for an African and Arab revolution. Together we will crush the last vestige of colonialsm."

The rest of Brown's speech and much of Carmichael's talk to the crowd were directed against another African Liberation Day march planned for next Saturday by the African Liberation Day Support Committee.

The two organizations began their argument, according to Lamin Jangha, because of differences over the role of blacks in the United States. The All-Africa group believes that "black people in (the United States) are not Americans," Jangha said. "They are Africans just like black people everywhere, in China, in Australia . . . .

"African Liberation Day is to build the party so black people here will return to their homeland (Africa) and reclaim the land. The struggle in this country will not be over until Africa is liberated."

The Support Committee believes that the homeland for blacks in the United States is the United States and uses African Liberation Day to "mobilize blacks, Afro-Americans, to fight for their rights in this country," according to one of their supporters who was handing out the committee's literature at yesterday's rally.

"They (the support committee) consider us fellow Americans," said a man who identified himself as Kaman, a native of the District who took part in yesterday's march. "We consider ourselves Africans and a part of the African revolution. They say all they are doing is supporting the revoultion in Africa."

Seale said yesterday's march was part of the 1970s link between the civil rights movement of the 1960s - in which Carmichael and his Student Nonviolent Coordinating Committee (SNCC) played a prominent part - and an economic revolution of the 1980s. Seale said the economic revolution will give black people an economic base in the United States.

"There wil be no true revolution in the United States until there is an economic revolution," Seale said, "and that day is coming to this country in the next 10 years."