A stern warning from Bridgeport officials after they say a fake explosive device tied up first responders for an hour and a half.

They say somebody used a peanut-butter jar and Play-Doh to fashion a bomb-like device, which was then left in somebody's mailbox on Wheeler Avenue Friday afternoon. 

Officials say it's a serious crime to scare the public and waste the valuable time of busy first responders.

"This type of hoax, this type of prank, it tied up several police units, several fire units, and several members of their DEEP and also the Connecticut State Police were responding with their bomb unit," says Chief Richard Thode. "So these types of pranks, though they seem kind of harmless, they really drain the resources of the community and the state."

Police say they're examining surveillance video to try and track down the person who planted that device.