Reported Threats Delay Mandela Release : South Africa: The government says warnings have come from both radical blacks and right-wing whites.

The government said Thursday that the security concerns holding up the release of jailed nationalist leader Nelson R. Mandela include threats against his life from both radical left-wing blacks and right-wing whites.

“We want him to get out of that prison and walk the streets of our country as a free man . . . and alive,” said Adriaan Vlok, the government minister of law and order. He added that arrangements for Mandela’s protection have not been completed, but will be made in consultation with the prisoner.

President Frederik W. de Klerk said last week that Mandela’s security and unspecified “personal circumstances” were the main things delaying the 71-year-old African National Congress leader’s release after more than 27 years in prison. However, anti-apartheid activists say the government may also be stalling while it studies reaction to De Klerk’s reform package and considers meeting more of the ANC’s conditions for negotiations.

De Klerk and his Cabinet ministers are counting on Mandela to help them get negotiations with the black majority under way. Mandela has used his position from inside South Africa’s prison system to play the role of facilitator for talks between the government and the ANC.

But Mandela is said to have made it clear to the government that the ANC will not sit at the table with De Klerk until he lifts the 3 1/2-year-old state of emergency and releases political prisoners. Fifteen activists, including Mandela, are serving life terms, and 2,500 are imprisoned for shorter terms for politically inspired crimes.

Both the ANC and the government worry about Mandela’s safety once he is freed. The government is considering round-the-clock police protection for Mandela, if he wants it, Vlok said. He added that allowing armed ANC members to protect Mandela is also being studied.

Police declined to specify the threats against Mandela. But Vlok said that threats from the right have increased in recent weeks and “most of their threats are centered around his release.” Militant right-wing groups, who are few but well-armed, say Mandela is a terrorist whose freedom will incite violence among blacks.

Over the last two years, Vlok said, police investigators have heard threats from black factions who are upset that Mandela has been playing the role of facilitator with the government.

That is one of the reasons the government has advanced for maintaining its remaining emergency regulations.

Vlok told Parliament on Thursday that the emergency is still needed because of the “extremely explosive political situation in the country at present.”

“There are too many irresponsible people who are only too eager to take advantage of existing problem areas in a reckless way,” Vlok said. “The revolutionary climate is still unnaturally high.”

As Vlok spoke, police in the Johannesburg township of Alexandra used tear gas to disperse several thousand blacks protesting a tour by an English cricket team. The team is defying an international ban on sports contact with South Africa.

Police said eight journalists covering the clash were briefly detained when they refused to leave. De Klerk ended most restrictions on press coverage of unrest last Friday, but the police said they were acting under other emergency regulations that empower them to order anyone to leave any area.

Police later used clubs to break up a smaller protest involving about a hundred people outside a Johannesburg building housing the British Consulate.

But in Port Elizabeth, more than 50,000 blacks marched peacefully to a government education office and presented a petition calling for better facilities for black education and an end to segregated schools.