A southern Illinois teenager remained in jail on Sunday after police said he threatened to shoot people at a high school prom.

Shane S. Bramlett, 18, from Ava, was arrested Saturday and charged with making a terrorist threat, intimidation, violating a protection order and telephone harassment, police said Sunday. He was being held in the Jackson County jail on $100,000 bond.

Family members reached in Ava, a community 20 miles from Carbondale, declined to comment on the arrest.

Murphysboro police officer Jeremy Kranawetter said Bramlett made threatening statements about an attack at the Murphysboro High School prom, leaving a message on his ex-girlfriend's cell phone. Police also listened in on a conversation between the two where the suspect reportedly made a similar threat.

Kranawetter said police didn't know if Bramlett attended the school.

The school's prom was held Saturday evening at the nearby Carbondale Convention Center and extra security was brought in to monitor the festivities. Pictures from the dance showed police waving metal-detector devices over the students as the entered the facility.

Kranawetter said the dance went on safely, without incident.