"The persons who have entered the building and have initiated the hostage-taking have locked the property, so it is not locked by police or other forces," the spokesperson added.
The chain said it was working to establish the names and nationalities of those taken.
Witnesses in the area said police had surrounded the hotel and were blocking roads leading into the neighborhood.
Northern Mali was occupied by Islamist fighters, some with links to al Qaeda for most of 2012 until they were driven out by a French led military operation.
