Numerous media houses remained outside a Pretoria hospital on Wednesday as former president Nelson Mandela spent his fifth day there being treated for a recurring lung infection.

More than ten outside broadcast vehicles were parked close to one of the hospital's entrances.

Security remained tight at the facility, with six police officers manning each entrance. All cars entering the facility were searched.

By 8am, no family members of the elder statesman had been seen entering or leaving the hospital.

On Tuesday, Mandela's ex-wife, African National Congress MP Winnie Madikizela-Mandela, left the hospital before 6pm.

She and her daughter Zindzi were driven off in a black Audi, escorted by a white Mercedes Benz. Both cars had flashing blue police lights.

Mandela's other two daughters, Makaziwe and Zenani, who is South Africa's ambassador to Argentina, were also seen at the hospital on Tuesday.

On Saturday, the presidency announced that the ailing icon had been admitted to hospital in the early hours of the morning and was in a "serious but stable" condition.

His condition had remained unchanged since then.

The presidency said on Tuesday that the doctors treating Mandela had given President Jacob Zuma a thorough briefing on Monday night.

"President Zuma has full confidence in the medical team, and is satisfied that they are doing their best to make Madiba better," spokesman Mac Maharaj said in a statement.

Mandela was still in a "serious but stable" condition.

This is the third time this year the Nobel Peace Prize laureate has been hospitalised.

At the end of March and in April, he spent nine days in hospital receiving treatment for recurring lung problems.

Earlier in March, he was admitted to a Pretoria hospital for a scheduled check-up and was discharged the following day.

Sapa