Police believe a pipe bomb-type device was the cause of an explosion in Mesa on Thursday night.
Mesa officials say officers responded to a report of an explosion in the Chelsea Park area near Val Vista Drive and Main Street. There they found pieces of a "pipe bomb type of device."
No one was injured in the explosion and officials say it happened in a water retention basin away from properties. An ABC15 viewer reported hearing the explosion from his backyard.
The investigation is still ongoing.