Nelson Mandela is making slow, but steady, progress in hospital, according to his family and the Presidency. File photo: Reuters

Pretoria - Police officers were searching all vehicles entering the Pretoria hospital where former president Nelson Mandela was receiving treatment on Sunday.

The Mediclinic Heart Hospital's two entrances, on Park and Celliers streets, were manned by South African Police Services members and security guards since Madiba was admitted to the private facility on June 8 with a recurring lung infection.

Motorists were being requested to open their boots as the cars were searched at the hospital's security check-points.

Two Tshwane metro police vehicles were stationed near the entrances. Some well-wishers arrived at the Celliers Street entrance and read the numerous get-well messages posted on the hospital's security wall.

A collection of flags, bouquets of flowers and multi-coloured paintings adorned the hospital's walls.

Earlier on Sunday, the Presidency announced that Madiba, 95, was slowly but steadily improving.

“The medical team also reiterated that although his health was improving steadily, Madiba still remained in a critical condition,” spokesman Mac Maharaj said in a statement.

The anti-apartheid icon has been critically ill in hospital for over two months. Sunday marked the ailing former president's 65th day in hospital.

Mandela's youngest daughter Zindzi Mandela told the SABC on Friday that her father was becoming more alert and responsive each day.

“Tata now manages to sit up, like now he is able to sit up in a chair for a few minutes in a day. Every day, you know, he is becoming more alert, more responsive and so on,” she said.

“Tata is determined not to go anywhere anytime soon. I cannot stress this enough. People must stop saying to the family 'let go, let go'. We are just looking at this man who is saying 'I'm not going anywhere',” she said as she left the hospital. - Sapa