The FBI is investigating the “suspicious package” and bomb threats that caused an evacuation at one of Virginia’s oldest, largest, and longest-running Civil War reenactments, Saturday.

The Frederick County Sheriff’s Office shut the event down after a visitor found a “suspicious package” near the Cedar Creek and Belle Grove National Historical Park around 4 p.m. Saturday. Due to its proximity to the Civil War reenactment, the sheriff’s office evacuated the event and shut down the festivities, a local NBC affiliate reported.

Authorities soon rendered the device safe, and no one was reported harmed. Participants were allowed back after police scanned the area for additional threats.

The sponsors of the event, the Cedar Creek Battlefield Association, had acknowledged that threats were made before the event began and had already arranged for increased security. The sponsors posted a notice to that effect on the event website several days ago.

“We would like to make everyone aware that the Cedar Creek Battlefield Foundation has received a letter threatening bodily harm to attendants of this event,” the event website read. “With this in mind security has been increased, and we ask that everyone work with us for a safe and enjoyable event. Please pardon the inconvenience as you may experience increased security measures when enjoying the event.”

After the incident with the device, Sunday’s activities were canceled.

This year’s event was set to commemorate the 153rd anniversary of the Battle of Cedar Creek and the event has been held annually since 1990. The reenactment is one of the largest annual events in the region drawing each year between 3,000 and 5,000 reenactors from all over the east and near Midwest as well as Canada.

Follow Warner Todd Huston on Twitter @warnerthuston.