Nobody can just disappear in the United States unless they have friends who can help them.

Tour spokeswoman Jane Hermann

The organisers said 17 members of the troupe of dancers and musicians of the Ballet d'Afrique Noire went out to celebrate after a performance at the University of California in Berkeley and never returned.

Some reports said they walked off the stage and mingled with the audience and apparently vanished.

"They've disappeared," said Jane Hermann, who is a spokeswoman for the New York-based ICM Artists Ltd - which has sponsored the trip.

"They did a beautiful performance at Zellerbach [Hall] on Sunday afternoon, they went out to celebrate and went hither and yon," she said.

Temporary visas

Ms Hermann explained that they only realised what had happened at noon on Monday, when only 11 members of the 28-strong Dakar-based group turned up as planned to be transported to Arizona, where they were scheduled to perform.

I have no idea what their desires are, or what their plans are

Ms Hermann

"I think they've been misguided by friends who live here," she suggested.

"I know they have friends in the Bay Area. ... Nobody can just disappear in the United States unless they have friends who can help them." Ms Hermann added.

The tour organisers have now cancelled the remaining three performances of the tour and the 11 remaining members of the troupe have flown back to Senegal.

The dancers and musicians were visiting the US on temporary visas which expire on 20 April.

It is not clear if the missing dancers are intending to apply for some form of asylum.

"We have no idea what happened, and I have no idea what their desires are, or what their plans are," Ms Hermann said.

The Immigration and Naturalization Service has been notified about the situation.

Ancient civilisation

The Ballet d'Afrique Noire is one of Senegal's oldest traditional music troupes.

It was established in 1958 and the company has been training about 150 members each year - many of whom regularly travel overseas to perform.

The troupe that went to the US had been performing 'The Mandinka Epic,' which is a collection of traditional music, songs, and dances from the ancient civilisation of Mali.