Mrs Habyarimana was detained in the Paris region (1977 file photo)
The widow of former Rwandan President Juvenal Habyarimana, whose assassination triggered the Rwandan genocide, has been arrested in France.
Agathe Habyarimana is accused by the current Rwandan government of helping to plan the 1994 genocide, and has long been sought by prosecutors there.
Mrs Habyarimana, who has been living in France for several years, denies the accusations.
More than 800,000 Tutsis and moderate Hutus died in the massacres of 1994.
French officials said Mrs Habyarimana was detained in the Paris region by police executing a Rwandan-issued international arrest warrant.
Diplomatic relations broken off 2006, restored late 2009
French judge said current President Paul Kagame had been behind President Habyarimana's assassination
Rwanda accused France of arming Hutu militias
Mrs Habyarimana, who was flown out of Rwanda by the French military in the early days of the violence, has been seeking political asylum in France, without success.
Her arrest follows a visit to the Rwandan capital Kigali last week by French President Nicolas Sarkozy, when he admitted that France - and the wider international community - had make "mistakes" over the genocide.
His comments followed years of strained relations between the two countries.
Diplomatic relations were restored late last year having broken down after a French judge said President Paul Kagame had been behind President Habyarimana's assassination, and Rwanda accused France of arming the Hutu militias involved in the 1994 genocide.
Mrs Habyarimana's lawyer said her arrest was directly linked to Mr Sarkozy's visit.
"You can't not draw a link," said Philippe Meilhac. "The extradition request from Kigali dates back to November and was obviously re-activated."
Rwanda has welcomed her arrest.
"We are encouraged by these new developments and the fact that the long arm of the law has finally taken its course," said Justice Minister Tharcisse Karugarama.
Mrs Habyarimana has now been freed on bail.
The BBC's Catherine Zemmouri in Paris says it is not clear if France will extradite her to Rwanda.
She says that French magistrates have recently refused to send three suspects to Rwanda fearing they would not receive a fair trial - an argument repeated by Mrs Habyarimana's lawyer.
France has, however, extradited suspects to the UN-backed International Criminal Tribunal for Rwanda (ICTR), based in Arusha, Tanzania.
President Habyarimana died in April 1994 when his jet was hit by a missile over the Kigali airport.
Hardline ethnic Hutu supporters of the president then launched the apparently pre-planned massacres.