Rwanda’s electoral commission has barred three candidates from running in next month’s presidential election, while allowing two opposition figures to stand against incumbent President Paul Kagame.
Amnesty International, meanwhile, warned that the election would be held under a "climate of fear" and repression.
Diane Shima Rwigara – hitherto the only female contender - Gilbert Mwenedata and Fred Sekikubo Barafinda have been barred from running.
Rwigara, who was standing as an independent, said last week that local leaders threatened her supporters while they were collecting signatures for her nomination.
Rwandans go to the polls on August 4. The choices on offer are Paul Kagame – President since 1994 - Frank Habineza of the opposition Democratic Green Party and independent candidate Philippe Mpayimana.
Habineza’s Greens are the only opposition party allowed to operate in Rwanda.
Observers say Kagame’s victory is overwhelmingly likely.
Rwigara was banned from the race after the head of the government electoral commission accused her of using the names of long deceased persons on her list of nomination signatures – as well as the names of others who belong to a rival political party.
Amnesty International said Rwanda has seen two decades of sometimes deadly attacks on political opponents, journalists and human rights activists. The NGO said major political reforms are necessary.
"Since the ruling Rwandan Patriotic Front took power 23 years ago, Rwandans have faced huge, and often deadly, obstacles to participating in public life and voicing criticism of government policy," Muthoni Wanyeki, an Amnesty official in East Africa, told AP.
Kagame’s government has been accused of responsibility for several killings and disappearances of opponents, journalists and human rights activists. He has led Rwanda since the end of the country's 1994 genocide.
The longtime President is often praised for bringing stability and higher living standards to the country. However, critics decry what they see as authoritarian tendencies in response to legitimate opposition.