Spain says al-Qaeda's North African cell is likely to be responsible for the apparent kidnapping of three aid workers in Mauritania.
Interior Minister Alfredo Perez Rubalcaba said "everything suggests" al-Qaeda in the Maghreb was involved.
Mauritanian police said the workers, from Barcelona Accion Solidaria, were attacked on a road linking the capital Nouakchott to the city of Nouadhibou.
Two men and a woman were snatched by armed men.
The three aid workers were in a four-wheel drive vehicle at the back of a convoy when they were attacked.
Julia Tabernejo, from Barcelona Accion Solidaria, told the Associated Press: "I think the others heard shooting, and when they stopped, the car was empty. Those three were no longer in it."
They had reportedly been delivering aid to Nouadhibou and were also dropping off donations along the route.
The kidnapping happened near the town of Chelkhett Legtouta.
"Though we can say absolutely nothing for sure at the moment, everything would seem to indicate that it was a kidnapping," said Mr Rubalcaba.
"If that's the case, as I fear it is, everything suggests that it is an AQIM [al-Qaeda in the Islamic Maghreb] kidnapping."
Analysts say Mauritania has generally been a peaceful country - but several attacks linked to the al-Qaeda cell have rocked the status quo.
An American teacher was killed in June, with al-Qaeda later claiming it had killed him for spreading Christianity.
In August a suicide bomber set off an explosion outside the French embassy in Nouakchott, injuring two guards.
And four French tourists were killed in December 2007.