Unknown attackers have kidnapped four European tourists near the border between Niger and Mali, Malian officials say.
Local officials say the hostages include two Swiss, one German and a Briton.
The Swiss foreign ministry confirmed two citizens were missing, while UK and German officials were checking reports.
Northern Mali has been the scene of clashes between the army and Tuareg rebels in recent years.
In a separate incident, the Malian government said on Thursday that the army had fought Tuareg rebels at a base in the north of Mali.
At least 31 Tuaregs died, but the government said there were no casualties on its side.
Last month at least 20 people were said to have been killed and several taken hostage in a rebel attack on a military base in northern Mali.
In the kidnapping incident, officials said the four Europeans were returning from the Anderamboukane festival on nomad culture in the border area when they were seized.
Their three-car convoy was ambushed; the first car got away and alerted the security forces, but the second and third cars, which were carrying the tourists, stayed on the spot and the people in them were kidnapped.
There were conflicting reports about exactly where the kidnapping took place, with AFP reporting that it was near Bani-Bangou in Niger, while Reuters said it was near Menaka in Mali.
The region is harsh desert. No group has claimed responsibility for the kidnappings.