The two thieves then fled on foot in the direction of Eich.
Dressed in dark clothes, both were described as being of slim build and were about five feet tall.
According to the victims, the two attackers spoke in French, one of the men had a black mask, the other's was blue.
Police urge citizens and motorists in the area to be cautious, and to avoid picking up hitchhikers.
People with information should report any suspicious behaviour to the 113 emergency number.
