DES MOINES, Iowa — A report of an active shooter at Lincoln High School on Thursday turned out to be a hoax, also known as a ‘swatting’ call.

At around 2:57 p.m. a 911 call was made reporting an active shooter in room 21 at Lincoln High School. Officers with the Des Moines Police Department swarmed the school unannounced, according to a Facebook post on the Lincoln High School’s page.

When police arrived and notified school officials of the 911 call it was determined to be a hoax. This conclusion was made due to the 911 call being made by an out of state number, no gunshots being heard, and the fact that the building doesn’t have a room 21, the school said in the Facebook post.

As a precaution, the school’s safety team went room to room to ensure all students and staff were safe. No threat was found.

A ‘swatting’ incident is defined in the Cambridge Dictionary as “the action of making a false report of a serious emergency so that a SWAT team, or a group of officers, will go to a person’s home, made by someone who wants to frighten, upset, or cause problems for that person.”

Some of the most well known ‘swatting’ calls have been made by Tyler Barriss, who was sentenced to at least 20 years for committing dozens of prank calls, including one that resulted in the death of an unarmed man in Kansas in 2017. ‘Swatting’ calls have also been made to the homes of White House advisor Steve Bannon and Parkland shooting survivor David Hogg.