NOUAKCHOTT Mauritanian military forces killed at least 12 members of al Qaeda's North African wing and suffered several fatalities in fighting along the border with Mali, a Mauritanian security source said on Saturday.
The clash is the latest sign of an escalation in the battle between Saharan countries and al Qaeda in the Islamic Maghreb (AQIM), the chief suspect in the kidnapping of seven foreigners, including five French citizens, in Niger on Thursday.
An early toll put the number of dead on the AQIM side at 12, with two Mauritanian soldiers killed, the source said. As fighting continued on Saturday the same source said the toll on both sides was rising, without giving more details.
"The operation was launched because the opportunity presented itself. It was not planned long in advance," said a second security source in the Mauritanian capital Nouakchott who knew the background to the mission.
The French Foreign Ministry said there was no connection to Thursday's kidnappings, in which a French employee of nuclear firm Areva and his wife were seized.
"This action is independent of the kidnapping of Areva employees. There are no French forces on the ground," a ministry spokesman said in Paris.
The seven hostages are believed to have been taken to Mali, a source in the Nigerien military told Reuters after an army search operation on Friday.
Security experts say al Qaeda allies are building a base in the desert region that straddles the porous and thinly policed borders of Algeria, Mali, Niger and Mauritania after being squeezed out of traditional areas along Algeria's coast.
French President Nicolas Sarkozy promised in July to punish AQIM for executing a 78-year-old French hostage after a joint Franco-Mauritanian commando raid failed to free him. AQIM in turn has said it would avenge its fighters killed in the raid.
The group has not claimed responsibility for Thursday's brazen kidnapping of foreigners in Niger's northern uranium mining zone, which has raised fresh doubts about the security of Western mining operations in the region.
Neither France nor the mining firms gave details of how the workers were seized. But a local businessman and a source in the mining industry in Niger told Reuters the foreigners were taken while they slept in their houses in the town of Arlit.
Among the hostages were five employees of Vinci, whose subsidiary Sogea-Satom is a contractor in the region.
The French Foreign Ministry urged its nationals on Friday to leave danger zones in Niger and an Areva executive said the company had called some of its staff back from Arlit.
Areva employs 2,500, the bulk of them local people, at three mine sites in Niger. Niger hopes to become the world's No. 2 uranium producer when the Imouraren mine comes on line in 2013 or 2014.
(Additional reporting by Abdoulaye Massalaatchi in Niamey; Tim Hepher in Paris; writing by Mark John; Editing by David Stamp)