(AP) — A vote on whether to end prohibition and allow alcohol on South Dakota’s Pine Ridge Indian Reservation is too close to call because of a high number of challenged ballots.

Tribal spokeswoman Tony Red Cloud says the measure got a majority of yes votes in the unofficial count — 1,645 to 1,494. But tribal president Bryan Brewer says because 438 votes were challenged — more than the difference — the outcome of the election won’t be known until those are checked.

He says in the next couple of days, election workers will verify that the people who cast those challenged ballots were enrolled members living on the reservation.

Brewer says vote challenges rarely change an election’s outcome.