Five teens could face criminal charges after they allegedly built a homemade bomb out of a plastic bottle and toilet cleaner.

Police Chief Brian Krueger said Austin police were sent to the 800 block of 10th Ave. SW in response to “shots fired” Sunday evening. Upon arrival, officers found pieces of an exploded plastic bottle in the alley. The bottle looked like it was filled with a soapy cleaner substance, Krueger said.

One of the teenagers told police they had used toilet cleaner and aluminum foil to cause the explosion.

Krueger said the police report has been forwarded to the County Attorney’s office for possible charges. The three 15-year-olds, 14-year-old and 17-year-old could be charged with unlawful possession of an explosive device.