The Robben Island Museum has lit a candle at the prison cell where former president Nelson Mandela spent 18 years of his imprisonment, it said on Monday.

"A candle is placed at cell number five," museum CEO Sibongiseni Mkhize said in a statement.

"In the courtyard where they [the political prisoners] used to break stones, a space is allocated for people who would like to drop flowers."

Mkhize said people were invited to pay tribute to Mandela by sending flowers and signing a condolences register at the gateway building, on the ferry, or on the island itself.

A memorial service would be held on Tuesday morning at the gateway building at the Cape Town waterfront.

The public was invited to join the Robben Island council and staff in the commemoration.

"It remains our collective moral responsibility to live the legacy of Tata Nelson Mandela," he said.

Mandela died at his home in Johannesburg on Thursday. His official memorial is in Johannesburg on Tuesday, and he will be buried in Qunu, in the Eastern Cape, where he grew up, on Sunday.