Rwanda faces a double test when it votes on Monday in its first election since a 1994 genocide: how far its wounds have healed after the slaughter of hundreds of thousands of its people and how democratic it has become.
Incumbent President Paul Kagame, 45, is widely expected to win the poll, which for the first time has more than one candidate. A Tutsi, Kagame has dominated politics since seizing Kigali at the head of a rebel army in 1994, ending the genocide.
He has boosted security, reduced poverty, kick-started economic growth and ethnic reconciliation. But critics say his government has an iron grip on Rwanda and question how democratic the election will be.
On Sunday, one of the four candidates quit the race, telling her supporters to vote for Kagame. Alivera Mukabaramba's campaign manager said she was withdrawing to protest what she saw as the use of ethnic propaganda by Kagame's main challenger Faustin Twagiramungu to try and win votes.
Nine years ago, extremists from the Hutu majority killed an estimated 800,000 Tutsis and moderate Hutus -- by many estimates more than 10% of a population that may have numbered no more than eight million -- in a three-month orgy of killing.
The genocide, believed to be the fastest of its scale in history, was the climax of decades of bloodshed, built on a tribal divide that colonialists cemented with biased policies.
Twagiramungu, a politically moderate Hutu, who stood against the genocide, has been accused of "divisionism" by Kagame and his Rwandan Patriotic Front (RPF) -- a dangerous term in a country still coming to terms with its bloody past.
Human rights groups say the RPF has regularly used the term to sideline opponents. Kagame denies it and says he will not tolerate any attempts to foment division.
"'Divisionism' here is...everything," Twagiramungu told a news conference on Sunday. "For me, if you do not follow the RPF here you are divisionist, full stop."
Twagiramungu, 58, who worked with the RPF in the first post-genocide government, has accused the party of trying to discredit him and said some of his election observers had been arrested on Saturday.
Police said 12 men were arrested in a bar in Kigali for holding an illegal meeting and were suspected of "hoping to co-ordinate acts of violence and disrupt elections".
The president's office issued a statement on Sunday saying it was shocked by an Amnesty International report that said the run-up to the election was marred by threats and harassment.
"The timing of the report could not be more damaging as it is intended to dismantle our gains of the last nine years," the statement said, describing the report as malicious and baseless.
Many of Kagame's critics say people in Rwanda are too scared to express themselves freely.
"We know the outcome well before the election takes place. This is a mockery of a democratic election," said Jeff Nsengimana, Tutsi vice-president of an exiled Rwandan opposition party in Canada.
Mukabaramba and fourth candidate Jean Nepomuscene Nayinzira had not been expected to make much impact at the ballot box.
The poll is being closely watched within the region, where Rwanda's rivalry with Uganda in eastern Congo casts a shadow over the Great Lakes' prospects for stability.
Voting stations will open on Monday. Around 3.9 million people are registered to vote in Rwanda, and more than 10,000 members of the diaspora were expected to take part at embassies around the world.