JOHANNESBURG, South Africa -- South Africa expects overwhelming crowds and a host of world leaders to attend services honouring late President Nelson Mandela, though with the ceremonies only days away officials acknowledged Saturday they couldn't offer any specifics yet.

Across the country, South Africans already have begun honouring Mandela, who died Thursday at age 95, and officials expect tens of thousands to participate in next week's official services.

In their first statement since Mandela's death, his family said they had "lost a great man," just as they had when South Africa's apartheid government imprisoned him for decades.

"The pillar of our family is gone, just as he was away during that 27 painful years of imprisonment, but in our hearts and souls he will always be with us," said the statement, read by family spokesman Lt. Gen. Themba Templeton Matanzima.

"His spirit endures. As a family we commit ourselves to uphold and be guided by the values he lived for and was prepared to die for," he said.

Official services honouring Mandela begin Tuesday with a major memorial planned at FNB Stadium on the edge of Johannesburg's Soweto township. Government Minister Collins Chabane told journalists Saturday he expects massive crowds far beyond what the stadium's normal 95,000-person capacity could hold. He said there would be "overflow" areas set up.

"We can't tell people not to come," he said.

He couldn't offer specifics about how crowds would arrive there with all roads to the venue closed by police or who would serve as a master of ceremonies.

Those planning Mandela's funeral include the former president's family, the federal government, the military and the African National Congress political party. Despite some prior planning by authorities as Mandela grew frail and suffered bouts of hospitalization in recent years, many of the details remain up in the air.

It's unclear which ceremony world leaders will attend, either Tuesday's stadium memorial or the planned funeral service Dec. 15 in Qunu, the Nobel Peace Prize laureate's rural hometown in Eastern Cape Province. Chabane said South African officials briefed diplomats Saturday about the arrangements, though they would leave it to foreign governments to say which event their leaders would attend.

U.S. President Barack Obama and his two predecessors, George W. Bush and Bill Clinton, already have indicated they will attend services in South Africa honouring Mandela. Many other world leaders also are expected.

Mandela's body won't be at the stadium event Tuesday, Chabane said. His body will rest in state Wednesday, Thursday and Friday at the Union Buildings in Pretoria, the seat of government power in South Africa's capital.

Mourners will walk up the steps into the Union Buildings' amphitheatre and file past Mandela's body, Chabane said. Authorities blocked visitors from visiting the amphitheatre Saturday. Chabane said he didn't know yet whether it would be an open- or closed-casket viewing.

Mandela's body will be held overnight those days at a military hospital on Pretoria's outskirts, Chabane said. He called on residents to line the streets to serve as an honour guard as Mandela's body will pass twice each day.

ANC members will hold a ceremony on Dec. 14 at Waterkloof Air Force Base near Pretoria before Mandela's body is flown to Qunu from there, Chabane said.

Sunday has been declared a national day of prayer and reflection over Mandela's death. On Monday, South Africa's two houses of parliament will hold special sessions to pay tribute to Mandela, the country's first black and democratically-elected president.

Tributes to the former anti-apartheid activist continued to pour in from around the globe. Zimbabwean President Robert Mugabe, who has been in power since his country's independence from Britain in 1980 and supported Mandela's ANC during its struggle against the apartheid regime, paid his first public tribute to the deceased leader.

Despite himself being accused by critics of increasingly authoritarian rule, Mugabe praised Mandela as a champion of democracy and "an unflinching fighter for justice."

"Mr. Nelson Mandela's renowned and illustrious political life will forever remain a beacon of excellence," Zimbabwe's state-run newspaper The Herald quoted Mugabe as saying.

Hundreds gathered Saturday at Mandela's house in Houghton. They sang liberation songs and walked past expansive, stately homes carrying bundles of flowers and images of Mandela.

Precious Ncayiyana, a pharmacist, carried a painting of Mandela made from old newspaper clippings about him. His left eye bore the number 46664, Mandela's former inmate number, while his right eye said Madiba, his clan name.

Ncayiyana said she planned to drive the painting's artist to Pretoria so he could make a painting of the leader's body lying in state.

"It's my way of contributing to Madiba's legacy. He's gone, but his spirit lives on," she said.

As the chanting and cheering behind her grew louder, she raised her voice to add: "If you see someone you can help, it doesn't cost anything. ... That's what he taught us."

Associated Press writer Ray Faure contributed to this report