PARIS (AP) -- Four Frenchmen taken hostage by Islamic extremists in Niger were released on Tuesday after three years of captivity and a French-led military intervention in the region that destabilized al-Qaida-linked radicals.
French President Francois Hollande announced the release and credited the president of Niger.
Niger Foreign Affairs Minister Mohamed Bazoum told The Associated Press the captives were freed in neighboring Mali and were taken to Niamey, Niger's capital. But Hollande and Bazoum provided no details about how the hostages had been released or where that had happened.
French Foreign Minister Laurent Fabius and Defense Minister Jean-Yves Le Drian have traveled to Niamey to bring the four Frenchmen home. Speaking from there on French TV, Fabius said the freed captives are "in good shape" now that "the nightmare is over."
Hollande had previously said that his government would not pay ransoms to free any French captives in West Africa, where hostage taking has been a lucrative business for Islamic radicals.
The four freed Frenchmen were captured in September 2010 by the North African wing of al-Qaida and spirited from their dormitories in the town of Arlit, Niger, where the French nuclear company Areva operates a uranium mine.
It had been thought they had been taken to northern Mali, where radical Islamists were operating, and officials confirmed they were in the far north of Mali.
In January, French forces invaded Mali to fight radical Islamic extremists in its north, killing or scattering them across the Sahel region. Hollande had said France's efforts to free captives in Africa were interrupted by the invasion, but then resumed.
The French-led military intervention clearly weakened the grip of the al-Qaida-linked AQIM radicals and other extremist groups, but has raised new concerns that they could make a comeback in Mali or neighboring countries.
On Tuesday, Hollande announced the release of the four captives -- Pierre Legrand, Thierry Dol, Marc Feret and Daniel Larribe -- during a trip to Slovakia. The French leader gave credit for the release to Niger President Mahamadou Issoufou, thanking him but not saying what he had done.
Areva chief executive Luc Oursel said in a statement, "This liberation is an immense joy for the families and for all Areva employees. The men showed extraordinary courage."
Rene Robert, the grandfather of Legrand, said: "What we lived through for three years I hope that no one else has to live through."
In an unrelated case, Frenchman Philippe Verdon, who was kidnapped in western African in 2011 in an attack claimed by AQIM, was found dead in Mali this year, with a shot to the head.
Pascal Lupart -- who was a close friend of Verdon's, and who runs an organization dedicated to helping to free French hostages -- alleged on Tuesday that Areva had paid a ransom to win the release of the four Frenchmen. But Lupart produced no evidence to back up his claim, and an Areva press officer, Julien Duperray, refused to comment about it.
French Defense Minister Jean-Yves Le Drian denied in an interview with TF1 television that any ransom was paid. "We don't play that game," he said.
Seven French hostages are still being held in other countries: two in the Sahel region, where Mali and Niger are located; one in Nigeria; and four in Syria.
Sarah DiLorenzo and Sylvie Corbet in Paris and Rukmini Callimachi and Krista Larson in Dakar contributed to this report.