JOHANNESBURG, JULY 21 -- A group of liberal white South Africans, who traveled optimistically to Senegal to open a peaceful dialogue with leaders of the outlawed African National Congress, returned to the reality of their home country today.

When 41 of the delegates arrived at Johannesburg's Jan Smuts International Airport they were met by a mob of angry white supremacists who shouted death threats and then attacked a small knot of student antiapartheid activists while hundreds of policemen looked on impassively.

As security forces hustled the delegation through a back door to safety, the airport terminal erupted into chaos. About 150 members of the neofascist Afrikaanse Weerstandsbeweging (AWB), or Afrikaner Resistance Movement, scuffled with students before leaving with threats to harm the leaders of the delegation returning from Dakar, Senegal.

Police chased and arrested several students, then seized at least a dozen foreign press photographers and television cameramen as authorities declared the airport a riot area and dispersed the crowds.

No one was injured, but for almost four hours the Jan Smuts terminal seethed with racial hatred, dramatically underscoring the volatility of the issue that had been brought into sharp focus by the meetings between dissident white Afrikaners and outlawed black South African nationalists in Senegal. That issue is whether whites should open talks with the ANC about the form a would-be postapartheid society would take in South Africa.

President Pieter W. Botha's government has branded the ANC a "terrorist" organization with which it will not negotiate.

The Afrikaner Resistance Movement does not call itself a a political party, and its size is not known.

The depth of the movement's racial hatred was evident in many incidents at the airport even before the Dakar delegates arrived. An airline hostess carrying a black infant for the child's crippled mother tried to walk through the gauntlet of protesters and was jeered until she retreated in fear to the passport control area.

AWB "storm troopers" wearing red and black Nazi-style armbands surrounded Rosemary Hunter, an antiapartheid activist from the University of the Witwatersrand, and shouted epithets and warnings like "Communist bitch!," "Rubbish!" and "Get out!" She was roughed up, but not hurt, before friends escorted her to safety.

As a group of about 12 students began to sing Nkosi Sikelel Afrika, or "God Bless Africa," the Xhosa-language hymn regarded as the black nationalists' anthem, the right-wing demonstrators charged at them, grappling with some and threatening to kill others as hundreds of police looked on.

One member of a rival extremist group, the Blanke Bevrydingsbeweging, or White Liberation Movement, rushed up behind an Indian who was passively watching the clashes and, shouting obscenities, tore off the man's glasses and hurled them to the floor.

Another struck a young woman without warning -- apparently because she looked like a student -- and sent her reeling.

Before the police formally declared over a bullhorn that the airport was a "riot area," obliging scores of journalists to observe emergency press restrictions and leave, the role of the police appeared to be ambivalent.

One of the returning delegates, Christo Nel, an Afrikaner business consultant from Johannesburg, said later that the group was met at the immigration hall by senior police officers who warned of an "ugly situation" unfolding in the adjacent waiting hall.

Nel said his group repeatedly requested that one of its leaders, Alex Borraine, cofounder of the sponsoring Institute for a Democratic Alternative for South Africa, be permitted to go outside and announce that an airport press conference, canceled by the authorities, would be rescheduled. He said a police commander warned that that would be too dangerous.

When it was announced that no press conferences would be held at the airport, AWB members lifted their leader, Eugene Terre'Blanche, to their shoulders. Terre'Blanche shouted, "They don't have the courage to look the Afrikaner people in the eye. Let the world know that they are not welcome in South Africa!"