A high school in northeastern Arizona was locked down as a precaution and there was no standoff with armed people inside as earlier reported by the local police chief, an FBI spokeswoman said.

A report that six armed people were holed up at Ganado High School on Wednesday on the nation's largest Indian reservation turned out to be false after authorities said they had evacuated students, said Deborah McCarley, a spokeswoman for the FBI.

"They are investigating the allegations there was a student or students that have or had weapons on school grounds today," McCarley said.

McCarley said she knew of no weapons that were found at the school.