Grieving South Africans, some in their pyjamas, poured into the streets on Friday morning after the death of former president Nelson Mandela at the age of 95.

Large crowds, some with vuvuzelas, gathered at his home in Houghton, Johannesburg, where he died surrounded by family around 8.50pm on Thursday evening.

Among those gathered were children. At the house in Vilakazi Street in Soweto, where Mandela once lived, candles were lit and roses placed in his honour.

Some people clad in African National Congress shirts sang struggle songs and the national anthem.

In Houghton, the spirit was of a celebration of his life as the national flag was hoisted and people held aloft pictures of Mandela at various ages.

Naledi Amos, 12, from Randburg, said she went to both homes to celebrate Mandela and his legacy.

"I know he fought for our freedom and now we go to school [and] we get equal education and resources, unlike... apartheid," the pyjama-clad girl said.

President Jacob Zuma broke the news of Mandela's death in a televised announcement, saying the Nobel laureate had died peacefully.

"He is now resting," said Zuma.

Flags around the country would be flown at half-mast from Friday until his funeral. Tributes and condolences flowed in for the man who led South Africa out of its dark apartheid days and into democracy.

People sent messages of support to the Mandela family on Twitter.

Among those who sent tributes were US president Barack Obama, his predecessors George HW Bush and Bill Clinton, Mandela's successor Thabo Mbeki, British prime minister David Cameron, Australian prime minister Tony Abbott, UN secretary general Ban Ki-moon, Britain's Prince William, and golfer Ernie Els.

Many tributes shared the same sentiment – that Mandela had left a legacy that would inspire generations.

Obama ordered flags to fly at half-mast at the White House and public buildings. His proclamation extended to US foreign missions, military posts, naval stations, and military vessels until sunset on Monday.

Mandela's close friend George Bizos told eNCA he would be missed, but his legacy would live on.

"None of us are immortal... It's very difficult to accept that he will no longer be around."

Bizos regularly visited Mandela when he was imprisoned on Robben Island during apartheid.

He said Mandela had contributed to a peaceful transition to democracy and would go down in history as a person who set an example to the world.