Members of the Congressional Black Caucus led hundreds of demonstrators on a march through downtown Washington yesterday that ended in a rally and a candelight vigil to protest what one speaker called the "living hell" created by South Africa's racial policies.

At a separate gathering yesterday before about 1,000 people at George Washington University, the Rev. Jesse Jackson called for an escalation in apartheid protest tactics to bring greater pressure on the Reagan administration and the South African government.

"We must go beyond the embassy and the consulates," Jackson said, alluding to the series of apartheid protests here and across the country that began last Nov. 21 when D.C. Del. Walter Fauntroy and two other black leaders were arrested inside the South African Embassy.

Jackson said apartheid protesters should attempt to persuade the Teamsters Union and the International Longshoremen's Association to stop loading cargo on ships bound for South Africa.

"We must ask [the unions] . . . and the people in those port cities to stop loading and unloading ships going to and from South Africa . . . . We must cut off apartheid at the jugular vein," Jackson said, in a speech that was interrupted repeatedly by applause from the mostly student audience.

Randall Robinson, executive director of TransAfrica, the foreign policy lobby that has led the apartheid protests, said after the rally that protests in port cities is a tactic under consideration by leaders of the antiapartheid movement, but that no final decision has been made.

Robinson, who marched and spoke at the black caucus demonstration, said the antiapartheid movement is circulating a "Freedom Letter" to collect 1 million signatures, and the letter will be presented later this year to Bishop Desmond Tutu, South African black leader and Nobel Peace Prize winner.

"We will try to take it to him in Soweto," Robinson told the rally. "If we're turned down we'll meet him in Zambia."

Robinson said in the interview that there are plans to take more direct action against U.S. corporations "in the not too distant future," but he declined to provide specific details yesterday.

About a dozen of the 20 members of the black caucus, including caucus chairman Mickey Leland (D-Tex.) and William Gray III (D-Pa.), chairman of the House Budget Committee, took part in yesterday's demonstration, as did other members of Congress.

The protest is a highlight of the caucus' 15th annual legislative weekend, an event that attracts hundreds of black politicians and officeholders from around the country to Washington.

South Africa is a major issue of this year's conference, which has as its theme "International Dimensions: The Reality of an Interdependent World."

Leland said in an interview that the caucus made South Africa a major theme at this year's conference because it wants to impress upon black politicians the importance of the antiapartheid movement.

Barbara-Rose Collins, a Democratic city council member from Detroit, and her mother, Versa Richardson, said they learned of yesterday's march when they arrived at the conference.

Richardson, who is 67, said the last time she marched was in a demonstration led by the late Rev. Martin Luther King Jr., whose wife, Coretta Scott King, spoke yesterday.

"I told my daughter I would like to march," Richardson said, as she walked down Pennsylvania Avenue yesterday. "I just felt like I would be contributing . . . . Sitting at home talking about it doesn't mean anything."