By Douglas Carew, Brendan Boyle, Caroline Hooper-Box and Sapa

Nelson Mandela sent a clear message to the government on World Aids Day on Saturday: people with HIV need drugs.

Mandela also said heads of state should lead the fight against Aids, which has already infected more than 40 million people worldwide.

"Heads of state and their first ladies must be in the forefront of the campaign to fight Aids," Mandela said, naming the leaders of Botswana, Uganda and Senegal as role models.

The former president and Archbishop Desmond Tutu, a fellow Nobel peace prize winner, spent Saturday speaking to children in Cape Town's Crossroads and Nyanga townships, spreading the message about fighting the spread of Aids.

Mandela's remarks come as the government continues to resist giving anti-retroviral drugs to people living with the HIV virus, and amid widespread criticism of President Thabo Mbeki's perceived lack of leadership on the Aids crisis.

On Saturday, Mbeki attended a meeting of the ANC's national executive committee. His spokesperson, Bheki Khumalo, said that Mbeki had been involved in World Aids Day "by way of institutions led by him".

Seated beside Tutu, Mandela said: "We must combine various strategies with giving people the necessary drugs to prevent the disease getting the upper hand."

If the government provided drugs and the proper nutrition and living conditions, it would bring down the level of HIV/Aids in the long run, he said.

Mandela said he had met Mbeki and Jacob Zuma, the deputy president, to tell them it was proper that they be seen in the frontline of the fight against the pandemic.

"For those who are HIV-positive, we must ensure that they get the proper treatment and drugs," he said while visiting a centre for children in Crossroads. He told those gathered there: "You must not leave this to the government. The question you should be asking is what are you doing to assist ordinary people who are fighting HIV/Aids."

Later on Saturday, Mandela rejected reports that he had attacked Mbeki's stance on Aids.

Speaking at the opening of the Nelson Mandela Gateway to Robben Island, the former president said journalists had misinterpreted the comments he had made earlier in the day at Crossroads and Nyanga.

Mandela had been shocked by a subsequent phone call from Mbeki's office about the reports.

"I said countries that have succeeded in bringing down the levels of Aids are those where the president of the country takes the lead," he said, to applause from the hundreds of VIPs at the ceremony.

He said he had quoted the case of President Yoweri Museveni of Uganda, and that of President Abdoulaye Wade of Senegal, two leaders who had "gone out in their countries and concentrated on mobilising the communities to understand how to fight Aids".

"After praising Museveni and Wade I said our president and deputy president are doing the same thing, but the difficulty with the president is that he is busy with Africa and countries beyond."

He added: "Some sections of the press are mischievously trying to drive a wedge between me and my president. They know I never criticise the president."

Khumalo said a commemoration service for people who had died of Aids had been held in the presidency on Friday, and that "most ministers were engaged with Aids-related activities yesterday".

"There has been a flurry of activity from government officials on this matter," Khumalo said.

This week, Aids activists and doctors took the government to court in an attempt to force it to provide the anti-retroviral drug nevirapine to pregnant women who have contracted HIV.

The drug reduces by 50 percent the chance of pregnant women passing the virus to their babies.

Government lawyers argued that the cost of providing such treatment would cripple the public health system, given the number of people who were infected with HIV/Aids, and questioned the efficacy of the drug.

Mbeki has said repeatedly that he is concerned about the safety of anti-retroviral drugs.

Speaking at the launch of the Democratic Alliance in Pietermaritzburg on Saturday, Tony Leon, the leader of the DA, called on the government to declare a national health emergency on Aids. The government's handling of the Aids crisis from 1994 to the present spoke of "massive denial and monstrous failure of leadership", Leon said.

Aids was the most serious threat to the people of KwaZulu-Natal. Quoting from official statistics on Aids relating to KwaZulu-Natal, he pointed out that 70 000 children had been orphaned by the disease and that an estimated 53 500 people had died in the year 2000 alone.

He reminded people that one in three residents of rural KwaZulu-Natal had contracted HIV.

The DA supported the Treatment Action Campaign's court action to demand that the health department implement mother-to-child anti-retroviral programmes in all public hospitals and clinics, he said.

Motsoko Pheko, the deputy president of the Pan Africanist Congress, speaking at the party's Gauteng provincial congress at Vista University, Soweto, on Saturday, said the government had been presented with enough information to prove that it was important to provide nevirapine to HIV-positive mothers.

Pheko said it was important that the government provided the anti-retroviral treatment to mothers so that unborn babies could be saved.

"I hope the court case brought against the government by the Treatment Action Campaign will force it to provide nevirapine to HIV-positive pregnant mothers," he said.

And at a rally in Cape Town, Zwelinzima Vavi, the general secretary of the Congress of South African Trade Unions, said the legacy of the past had facilitated the spread of Aids.

Vavi said the disease thrived on violence and the oppression of women.