Explosive device detonated near Catasauqua, Pennsylvania, polling place, police say

No one was injured when an explosive device detonated near a polling place in Catasauqua, Pennsylvania, during Tuesday's primary election, police said. 

Someone threw an explosive device out of a moving car toward Salem United Church of Christ, which serves as a polling place, around 9:15 a.m. The device detonated about half a block away from the church and around the corner from the entrance, Pennsylvania State Police said. 

The polling place on the 600 block of 3rd Street stayed open throughout the incident, state police said. Investigators believe this is an isolated incident.

Because of the investigation, 3rd Street is closed at Pine and Walnut streets. No one has been arrested in connection with the device, police said in an update around 5:30 p.m. Tuesday.

Anyone trying to vote at Salem UCC should enter from 4th Street, the fire department said.

"Local, state and federal law enforcement are all aware of the situation and monitoring both for community safety as well as compliance with election law," Lehigh County District Attorney Gavin Holihan said in a statement.

Emily Stratton, who lives near the church and works at the preschool there, said she heard the explosion from her house. The preschool was closed Tuesday because of the election.

"I seriously thought that somebody crashed into a house outside. It was just very loud and because of the houses, where they're located, it like echoed, so obviously it sounded louder than it probably was but because it was so close, to me it sounded like a car crash," Stratton said.

Pennsylvania State Police are investigating the incident with help from the Bureau of Alcohol, Tobacco, Firearms & Explosives, Catasauqua Borough Police, PSP Troop M Fire Marshal Unit, Allentown Bomb Squad and North Catasauqua Borough Police.

The polling place is located in Pennsylvania's 7th Congressional District.