War-torn Zambia gave Queen Elizabeth of Britain a colorful, carefree welcome today which was notably lacking in tight security despite fears in Britain for her safety.

Many in the spirited crowd of more than 5,000 at Lusaka airport broke through the thin security ranks and chanting and singing, surged around the queen and Zambian President Kenneth Kaunda.

Earlier this month there had been pressure in Britain to cancel the queen's nine-day visit to Zambia and switch the site of next week's Commonwealth conference which she is to attend because of fears that she could be endangered by the presence of Patriotic Front guerrilla forces of joshua Nkomo.

Just hours before the queen's arrival, Nkomo announced that he would not accept an invitation from Kaunda to participate in social functions for the queen, thus avoiding a politically embarrassing meeting for both the Zambian and British governments.

Nkomo cited "an indecent controversy in Britain about the queen's visit and the prospect that she might be put in a position of having to meet with the guerrilla leader. His forces, based in Zambia, have been fighting in the neighboring breakaway colony of Rhodesia for six years.

Any such meeting could have been politically difficult for British Prime Minister Margaret Thatcher whose Conservative government has moved toward lifting economic sanctions against the new black-led Zimbabwe-Rhodesian government of Prime Minister Abel Muzorewa. The British mission here had no comment, saying it was a Zambian matter, but there was an obvious sense of relief.

A banner-headlined story on the front page of the right-wing Sunday Express newspaper earlier this month reflected some British conservative sentiment against Nkomo. The paper talked of fears that the queen would be forced "to shake the bloody Marxist terrorist hand" of the plump, middle-aged guerrilla leader.

A spokesman for Nkomo's Zimbabwe African People's Union called "wild speculation" the conjecture that Kaunda only issued the invitation in the knowledge that the guerrilla leader would turn it down. Nkomo has routinely attended such functions in the past.

Signs of the deepening war in Zimbabwe-Rhodesia were evident in the queen's arrival from neighboring Botswana. For the first time in her four-nation tour, political posters were in evidence.

One told her not to "sell out" on the Zimbabwe-Rhodesia issue at the 40-nation Commonwelath conference of former British colonies. Another said "Muzorewa wears a bloody priest collar on his neck" and added that former Rhodesian prime minister Ian Smith "drink Zambian and Zimbabwean blood." Zimbabwe is the African name for Rhodesia.

The queen's flight from Botswana skirted Zimbabwe-Rhodesia and flew over Livingstone, site of Victoria Falls and the location of a Rhodesian raid into Zambia last week.

Zambian troops lined the roof of the airport and one machine gun could be seen, but security on the ground was minimal as cheering Zambians chanted "K.K.-Queenie" in honor of their president and the royal visitor. The queen who has also visited Tanzania and Malawi on her tour, was accompanied by her husband Prince Philip and their son, Prince Andrew.