American blogger Jammal Harraz, who posts videos on the internet under the pseudonym “Arab Andy,” carried out a prank at the University of Washington—in the US—by turning on a sound recording of a bomb and a blast, reported the Seattle Police.

The prankster video recorded the whole incident.

He entered a classroom in this university holding a cell phone, asked everyone to pay attention for a moment, and subsequently, he played a recorded message announcing “the C4 is charged,” and a countdown began.

This announcement caused panic, whereupon the “explosion” occurred.