Paris: Al Jazeera television aired pictures on Thursday showing seven hostages, including five French citizens, for the first time since they were kidnapped by al Qaeda in Niger two weeks ago.
In Paris, the French Foreign Ministry said it had authenticated the photos which the Arabic TV channel said had been released by the North African wing of al Qaeda (AQIM).
They showed the seven -- six men and one Frenchwoman -- looking healthy and sitting on sand in a desert setting, with several armed men in traditional Bedouin clothing and turbans standing over them and sitting alongside them.
The group, which included men from Togo and Madagascar, were casually dressed and appeared to be relatively clean.
"The (pictures) have been authenticated even if we do not know when they were taken," said French Foreign Ministry spokesman Romain Nadal. "They are an encouraging sign in that they show the hostages to be alive."
France says the hostages are being held in a mountainous region across the border in northwestern Mali.
US-based Site Intelligence, a group that monitors insurgent communications, also released an audio recording in French posted by AQIM`s media arm on Islamic websites.
In the recording, each hostage was asked in French to give their name, home town, age, marital status and to say when they had been kidnapped and by whom.
Anne Giudicelli, a former French diplomat who heads the Terrorisc think tank that also monitors Islamist forums, said copies of the pictures which she had obtained were dated September 28.
There had been no previous proof that the hostages, employees of French firms Areva and Vinci, were still alive after their abduction from their homes in the mining town of Arlit.
The kidnapping marked an escalation between Paris and AQIM, which executed 78-year-old French hostage Michel Germaneau in July after French commandos took part in a failed raid to free him. It vowed to avenge the raid.
France has not received any demands from AQIM since the workers were kidnapped but has said it would consider negotiating with the hostage takers for their release.
The abductions in Niger`s northern uranium mining zone were the latest in a string in the Sahel region of Africa that AQIM has claimed. Niger provides about a third of the uranium used in France`s nuclear power plants.
Until now militants had not been active in the mining area.
France is on heightened alert for possible attacks at home after receiving a tip-off that a female suicide bomber was planning to attack the Paris metro system last week.