Kagame is widely expected to win a second seven-year term in elections on August 9. He has held de facto power since 1994 when his guerrilla force took over after ending massacres of some 800,000 ethnic Tutsis and moderate Hutus by Hutu authorities.
Police spokesman Eric Kayiranga said opposition presidential hopeful Bernard Ntaganda had been taken in for questioning.
“The charges are divisionism based on ethnicity, gathering people without permission, creating groups of people that are suspected of being criminals and attempted murder,” Kayiranga told Reuters.
Ntaganda was suspected of being behind a plot to murder Christine Mukabunani, the leader of a splinter group in his PS Imberakuri party, earlier in the year, said Kayiranga. “(Ntaganda) has not been charged yet, we will continue working on it. We are still collecting evidence,” he added.
In December last year Ntaganda denied senate charges of peddling ethnic “divisionism” and genocide ideology.
Kagame has won praise for economic reforms and completely rebuilding state institutions since 1994 but international rights groups and the United States, a major donor and military ally, have expressed growing concerns about democratic freedoms before the elections.
Police also rounded up opposition supporters the day Kagame lodged his papers at the National Election Commission, but reports differed on how many people were involved.
Opposition leader Victoire Ingabire, who is also a presidential hopeful, said members of her United Democratic Forces party which mainly represents Hutus had been detained during a peaceful protest in Kigali.
“I think more than 100 were arrested,” said Ingabire, who is facing trial on charges of genocide denial and belonging to a terrorist organisation.
However, Kayiranga said that only 20-30 people had been arrested across the capital for causing disorder.
Ingabire’s party and the Democratic Green Party have called for the presidential election to be postponed to allow the parties to meet technical requirements to register. They are the only parties that have not been able to register.
A Reuters witness saw several Ingabire supporters arrested at the Justice Ministry as they unfurled party banners. Reuters