Two Swiss tourists have been kidnapped by Tuareg rebels in eastern Mali, the Swiss foreign ministry has confirmed.
A German and a Briton were also abducted on Thursday at Menaka, near the border with Niger.
The tourists had been at a festival for Tuareg culture when they were intercepted by a group of rebels, according to a senior Malian military officer.
They were taken from their car and driven to Niger. Three tourists travelling in another vehicle escaped the attack and alerted the Malian authorities, the German tour operator Oase Reisen said on Friday.
The foreign ministry said it was in contact with local authorities.
Thursday's abduction was the worst such incident in the West African desert state since an Islamic rebel group kidnapped 32 European tourists in the Sahara in 2003, holding some of them for six months.
For more than a year Tuareg fighters have attacked army posts and convoys to demand greater rights for their people, but doubts persist about the participation of veteran chieftain Bahanga, who is seen as a rogue element in the Malian Tuareg armed movement.