Rwandan President Paul Kagame has claimed a landslide victory in his country's election.
Kagame supporters have been celebrating already
In the capital, Kigali, thousands of his supporters have been celebrating, cheering and sounding car horns.
But the main opposition candidate, Faustin Twagiramungu, rejected the result on the grounds of fraud and intimidation.
With around half the votes counted, more than 94% of them were for Mr Kagame, according to the Rwandan electoral commission.
They are Rwanda's first democratic elections since the 1994 genocide in which 800,000 people were killed.
Turnout is reported to have been around 80%.
Mr Kagame is an ethnic Tutsi who led the rebel movement which ended the slaughter of the Tutsi minority and moderate Hutus by Hutu extremists.
"There is no doubt that the polls have gone our way," the president
told thousands of cheering supporters at the capital's Amahoro
(Peace) football stadium.
"This is a true victory, irreversible, and not a surprise."
The BBC's Andrew Harding says the figures prove that the former soldier has won support from across Rwanda's ethnic divide.
As a referendum on the president's rule, he says, it is an impressive result and a tribute to the stability and reconciliation which his government has promoted.
Before voting started, Mr Kagame appealed to people to vote as Rwandans, not as Hutus, Tutsis or Twa in the poll.
Radio Rwanda said the president of the National Electoral Commission, Dr Chrysologue Karangwa, had praised Rwandans for their peaceful participation in the elections despite a few problems of officials directing voters whom they should vote for.
The head of the European Union observer team said the election had gone smoothly.
"Everything we've seen in Kigali has gone ahead in a calm and orderly fashion. There's no problem," said Collette Flesch.
Our correspondent says this is the first time that Rwandans actually have the opportunity to vote for opposition candidates.
But critics say the opposition has been virtually excluded from the process.
Mr Twagiramungu, the main challenger, is a moderate Hutu former prime minister. He complained that he was unable to campaign freely.
On the eve of the poll, 12 of his supporters were arrested for allegedly planning to "co-ordinate acts of violence" in the provinces.
Speaking to Reuters news agency, he threatened to challenge the results in the court.
"I do not accept this election...That's not democracy. They are trying to have a Stalinist style one-party system. Almost 100%? That's not possible. I will write a letter to the Supreme Court."
Other opposition members accused Mr Kagame's government of exploiting fears of a return to ethnic conflict to stifle dissenting voices.
On Sunday Alivera Mukabaramba withdrew from the race and advised her supporters to back Mr Kagame, her spokesman said.
Her withdrawal left only one other candidate in the race apart from Mr Twagiramungu - Jean Nepomuscene Nayinzira.
Our correspondent says Mr Kagame is likely to face growing international pressure to use his new mandate to accelerate the process of democratisation in Rwanda.