Police searching for 1 of 2 people accused of throwing explosive device near polling place in Catasauqua, Pa.

Police in the Lehigh Valley are looking for one of the people responsible for throwing an explosive device toward a polling place in Catasauqua, Pennsylvania, during Tuesday's primary election.

Pennsylvania State Police said an explosive device was thrown 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 a block away from the church on the 600 block of 3rd Street. No one was injured and the polling place stayed open throughout the incident, according to state police.

On Wednesday, a father and son — Matthew Pletz, 57, and Jack Pletz, 25 — were charged after 17 illegal homemade explosives were found inside their 1998 Chevrolet pickup truck. Both are charged with weapons of mass destruction, risking catastrophe and related offenses.

Matthew Pletz was arrested on Tuesday night and is being held in Lehigh County Prison on $50,000 bail, District Attorney Gavin Holihan said during a press conference Thursday afternoon.

Holihan says that at this time, Jack Pletz is not in custody, and a warrant is out for his arrest. Investigators are asking anyone with information on where Jack Pletz is to contact police.

Holihan said his message for Jack Pletz is, "It's always safer and easier when you turn yourself in."

This is a developing story and will be updated.