HUNTSVILLE, Ala. (AP) — Police say a prank is to blame for a shooting scare at a combined elementary-middle school in Alabama.

Dozens of police arrived at the Williams School in Huntsville on Wednesday after police received a report of a shooting. A school spokesman says authorities initially believed they were dealing with an active shooter.

With parents gathered nearby, authorities say officers went through the school room-to-room and found nothing. Police later sent a tweet saying they responded to a call that turned out to be a prank.

The scare marked the second time in three months that Huntsville authorities have dealt with a false shooting report.

Officials shut down the Army’s Redstone Arsenal in Huntsville in June before determining that a report of an active shooter was false.