Paris, France (CNN) -- The French foreign ministry Thursday said a photograph of seven hostages in Niger -- including five French nationals -- has been authenticated and is an "encouraging sign" showing the hostages are alive.
"On September 30th a television network broadcast a photograph of the seven people who were kidnapped in Arlit [Niger] on September 16th, including five French nationals," the foreign ministry statement said. "Even if we do not know what date it was taken, it is an encouraging sign as it shows all the hostages alive. All state services are mobilized and are doing everything they can to free them."
The photograph was also posted on an al Qaeda-linked website, along with audio of what appeared to be the hostages responding to rapid questions from an unknown man.
Al Qaeda in the Islamic Maghreb (AQIM), the terror movement's affiliate in North Africa, claimed responsibility for the abductions of the six men and one woman, who are all linked with the French nuclear reactor builder Areva. The group included an Areva employee and his wife, along with five subcontractors who worked for the French construction firm Vinci.
A spokesman for French President Nicolas Sarkozy's office said Sunday that France was "ready to discuss" the hostages' release.
On the recording, four men and one woman are heard giving information, including name, age, nationality, hometown, job title and marital status. All the hostages said they are French and gave the names of French cities as their hometowns. One man and the woman, who said they are married, gave their ages as 59 and 62. Three others said they are 25, 30 and 33.
The photograph showed seven people sitting on the ground. Six were men, and the seventh person's face was intentionally blurred. Behind them stood people with covered faces, carrying large guns.
Officials for Areva and Vinci say they have beefed up security measures for their employees in the area and are working closely with both Nigerien and French authorities to secure the release of the hostages.
French military planes have been flying reconnaissance missions from the airport in Niamey, Niger's capital, trying to locate the hostages or their abductors.
Areva has been mining uranium for the past four decades in Niger, one of the poorest countries in the world.
French director Michel Germaneau was abducted in Niger and executed in July in nearby Mauritania. A video showed Germaneau's photo along with images of the French flag and al Qaeda in the Islamic Maghreb's black-and-white flag.