South Korea on Friday deployed 15,000 riot police in central Seoul as the funeral of former President Roh Moo-Hyun began, amid fears a national outpouring of grief would spark anti-government protests.
Roh leapt to his death Saturday from a clifftop near his retirement village after being questioned as a suspect in a corruption investigation.
The liberal leader who held office from 2003-8 has become a martyr in the eyes of his supporters. They say the current conservative government launched a politically motivated probe, a claim it denies.
"You are my president for eternity" read one popular placard displayed by mourners around the city's imposing Gyeongbok palace, where the service began at 11:00 am (0200 GMT).
The Seoul Police Agency said 15,000 police were on duty close to the former royal palace where streets were lined with yellow balloons -- Roh's campaign colour when he won an upset election victory in 2002.
Mourners wore yellow paper eyeshades and smiling portraits of the 62-year-old former leader were printed on balloons and banners.
"We came to pray for his soul," a Catholic nun waiting outside the palace told Yonhap news agency. "I barely slept last night. Too many thoughts crossed my mind and I was overtaken by emotions."
The committee organising the funeral said that as of Thursday morning, some three million had paid tribute at altars across the country, including one million who visited Roh's home village of Bongha.
The funeral procession left Bongha, 450 kilometres (281 miles) southeast of Seoul, at 5:00 am as his widow, children and closest confidants watched.
TV footage showed villagers weeping and praying as the hearse was carried on to a convoy.
Roh's popularity was low when he ended the single five-year term which South Korean presidents serve. In death, his reputation has soared.
The self-educated lawyer and rights activist was credited with easing authoritarianism and advancing democracy in a country which only overturned military-backed rule in 1987.
Deep divisions remain between liberal and conservative factions.
US Secretary of State Hillary Clinton paid tribute Thursday at Seoul's embassy in Washington. "President Roh's dedication to democracy and human rights are values the United States and the Republic of Korea share," she said.
Roh also pushed for reconciliation with North Korea and held a summit with its leader Kim Jong-Il in 2007.
He campaigned while in office to end the country's pervasive culture of corruption. But on April 30, in a nationally televised TV spectacle, state prosecutors questioned him about six million dollars which his family members received from a wealthy shoe manufacturer.
Roh, the country's third former president to appear before prosecutors, never admitted personal wrongdoing but apologised on his family's behalf.
Supporters including his predecessor Kim Dae-Jung say Roh was publicly humiliated despite the lack of evidence against him personally.
The government rejected Kim's request to speak at the funeral, according to a former aide to Roh.
Some 3,000 people were attending the funeral in the palace courtyard, including President Lee Myung-Bak and former presidents Kim Dae-Jung and Kim Young-Sam, lawmakers, diplomats and ordinary citizens.
A large screen broadcast the ceremony live for those unable to enter the palace.
Roh's body was to be cremated after the funeral and the ashes will be taken back for burial near Bongha.