School was canceled Friday at Washburn High School in Minneapolis as police and administrators investigated a threat.

School district officials did not disclose the nature of the threat, but district spokesman Dirk Tedmon said classes were called off because there was not time to complete a thorough investigation before they were to begin. The threat was reported late Thursday.

"In order to ensure the safety of students and staff, we are taking the unusual step of canceling classes at Washburn Friday," Tedmon said. "This will allow us to continue partnering with the Minneapolis Police Department to thoroughly investigate the situation."

School officials learned of the threat from a report made at the school, authorities said.