JOHANNESBURG: South Africa prepared Friday for tens of thousands of people to attend Jacob Zuma's inauguration, while brushing off concerns over a guest list that includes officials from North Korea and Sudan.

Zuma will be sworn in Saturday as the fourth president since the fall of apartheid, with almost 100 foreign delegations -- including nearly 30 heads of state -- set to attend with 30,000 onlookers gathered on the lawns at the seat of government in Pretoria.

The chief justice of the Constitutional Court, Pius Langa, will administer the oath of office to Zuma, who led the ruling African National Congress to a thumping victory in general elections last month.

South Africa's first democratically-elected president Nelson Mandela has been invited but has yet to confirm if he will attend.

But it is the high-profile visitors from countries with dictatorial or scandal-plagued governments that have sparked loud complaints among activists here.

"We know that having a variety of political leaders will give rise to a range of views. You can be sure our security will take account of this," top foreign ministry official Ayande Ntsaluba told reporters.

Activists have already started protesting over Zimbabwe President Robert Mugabe's visit, with pressure group Afriforum hanging posters in Pretoria reading "Mugabe, Go Home!"

Police quickly took down the signs, but Zuma is already under pressure to take a tougher line on Mugabe than his predecessor Thabo Mbeki, who brokered a power-sharing deal but was often criticised for being too soft on Zimbabwe's long-ruling ZANU-PF party.

Human Rights Watch urged Zuma to ensure that Mugabe follows through on promises to reform tough media laws and guarantee political freedoms.

"The new government of President Zuma should establish early on that it is committed to playing a positive role in ending repression and abuses," said Georgette Gagnon, the group's Africa director.

"Zimbabwe is an obvious place to start."

South Africa also faces complaints over invitations extended to King Mswati III of Swaziland, Africa's last absolute monarch, and Sudan President Omar al-Beshir, who is the target of an international arrest warrant on war crimes charges.

Zuma's allies in labour unions have vocally opposed the invitation extended to Mswati, who has not yet confirmed if he will attend.

"The presence of this despot at the inauguration will be an insult to all the people of Africa. It will give him credibility and democratic credentials which he does not deserve," the Cosatu labour federation said in a statement.

The foreign ministry's Ntsaluba said Beshir will not attend, sparing South Africa a diplomatic dilemma with Sudan.

If he did show up, South African authorities would be obliged by treaty to arrest him for the International Criminal Court, which issued a warrant for him on March 4, accusing him of crimes against humanity and war crimes in the western Sudanese region of Darfur.

Sudan will send a delegation, but Ntsaluba did not say who would lead it.

The South African Litigation Centre, a rights watchdog, said it has two lawyers on stand-by in the event that Beshir does show up, to ensure that the government follows through with his arrest.

North Korea, which sparked fresh international concerns over its nuclear programme with a long-range rocket launch on April 5, is sending its number two official Kim Yong-Nam, according to South Africa's government.

Major western countries are sending lowering ranking officials, including Britain's junior foreign minister Mark Malloch Brown, US Trade Representative Ron Kirk, and French secretary of state for human rights Rama Yade.