Rwandan opposition leader Victoire Ingabire has been arrested and accused of genocide denial and collaborating with a "terrorist organisation," reports Agence France-Presse.

The news agency quoted an anonymous government official as saying that Ingabire had been arrested in Kigali on Wednesday.

"She is accused of collaborating with a terrorist organisation, dividing the population, denying and downplaying the genocide," the official told AFP.

Ingabire plans to contest August's Rwandan elections as leader of the United Democratic Forces (UDF) party.

In Brussels, Eugene Ndahayo, president of a group calling itself the UDF-Inkingi Support Committee, condemned the arrest as a "barbaric and unlawful act."

He added: "It is a tragedy for Rwanda that a call for justice for all Rwandans irrespective of political and ethnic affiliation and for an all-inclusive national dialogue to give their views on how to put in place institutions that reassure every Rwandans is turned into accusations of genocide ideology, divisionism and collaboration with a terrorist organisation FDLR [the Democratic Forces for the Liberation of Rwanda]."

Since Ingabire began to campaign for the presidency, she has come under sustained attack from the Rwandan government and the government-supporting press, notably the New Times newspaper of Kigali.

In a recent interview with Radio Netherlands, Augustin Nkusi, spokesman for the Rwandan prosecutor general, claimed that Ingabire was collaborating with the FDLR, which includes remnants of the genocidaires of 1994.

"There is also evidence that she is busy creating an irregular armed force parallel to the regular national forces to come destabilize the country," Nkusi added. He also accused her of "throwing about statements of an ideology of genocide.”