Police are trying to find a man suspected of leaving an explosive device outside a Wal-Mart store in Boone, North Carolina, that was disabled by a bomb squad.

Police told The Winston-Salem Journal on Tuesday that a surveillance video showed a man running up to the store around dawn Sunday and leaving a smoking device before running away. A Wal-Mart employee who opened the store called 911 and reported spotting a ‘homemade bomb’ out front.

A police bomb squad disabled the device by shooting streams of water at it. Authorities said the device ignited and caught fire before fizzling out.

They said the device could have caused serious injuries. Federal and local investigators are now trying to identify a young man seen on a grainy videotape.