HAVANA (AP) -- Thousands of Cubans lined the streets of Havana Wednesday morning, some sleeping on sidewalks overnight, to bid goodbye to Fidel Castro as his ashes began a four-day journey across the country he ruled for nearly 50 years.

A caravan carrying the ashes was scheduled to leave the capital's Plaza of the Revolution after 7 a.m. for a journey from Havana to the eastern city of Santiago. On Tuesday night, tens of thousands of Cubans jammed the plaza as the presidents of Cuba, Mexico, Ecuador, Bolivia, Venezuela and South Africa, along with leaders of a host of smaller nations, offered speeches paying tribute to Castro, who died Friday night at 90.

The crowds at the rally and along Wednesday's procession route were a mix of people attending on their own and groups of Cubans organized by their government workplaces in group trips that are not strictly obligatory but create strong pressure to attend. Some groups of government workers slept on the streets because all public transport had been commandeered to move people to Castro-related activities. 

"We love the commandante and I think it's our obligation to be here and see him out," said Mercedes Antunez, 59, who was bused in by the state athletics organization from her home in east Havana along with fellow employees.

Cuban state media reported that the urn containing Fidel Castro's ashes was being kept in a room at the Defense Ministry where President Raul Castro, Castro's younger brother and successor, and top Communist Party officials paid tribute.

Tuesday's rally began with black-and-white revolution-era footage of Castro and other guerrillas on a big screen and the playing of the Cuban national anthem. Raul Castro closed the rally with a speech thanking world leaders for their words of praise for his brother, whom he called the leader of a revolution "for the humble, and by the humble."

South African President Jacob Zuma praised Cuba under Castro for its record on education and health care and its support for African independence struggles.

Castro will be remembered as "a great fighter for the idea that the poor have a right to live with dignity," Zuma told the crowd.

During the day, lines stretched for hours outside the Plaza of the Revolution, the heart of government power. In Havana and across the island, people signed condolence books and an oath of loyalty to Castro's sweeping May 2000 proclamation of the Cuban revolution as an unending battle for socialism, nationalism and an outsize role for the island on the world stage.

Inside the memorial, thousands walked through three rooms with near-identical displays featuring the 1962 Alberto Korda photograph of the young Castro in the Sierra Maestra mountains, bouquets of white flowers and an array of Castro's medals against a black backdrop, framed by honor guards of soldiers and children in school uniforms. The ashes did not appear to be on display.

Signs read: "The Cuban Communist Party is the only legitimate heir of the legacy and authority of the commander in chief of the Cuban Revolution, comrade Fidel Castro."

"Goodbye commander. Your ideas remain here with us," 64-year-old retiree Etelbina Perez said between sobs, dabbing at her eyes with a brown handkerchief. "I feel great pain over his death. I owe my entire life to him. He brought me out of the mountains. I was able to study thanks to him."

The scene was played out on a smaller scale at countless places across the country as the government urged Cubans to reaffirm their belief in a socialist, single-party system that in recent years has struggled to maintain the fervor that was widespread at the triumph of the 1959 revolution.

After 10 years of leadership by Raul Castro, a relatively camera-shy and low-key successor, Cuba has found itself flooded once again by the words and images of the man who dominated the lives of generations. Since his death on Friday night, state-run newspapers, television and radio have run wall-to-wall tributes to Fidel Castro, broadcasting non-stop footage of his speeches, interviews and foreign trips, interspersed with adulatory remembrances by prominent Cubans.