WINDER, Ga. (AP) — A Georgia high school was put on lockdown Wednesday and students gathered in its football stadium.

Helicopter video from WSB-TV showed dozens of law enforcement and emergency vehicles surrounding Apalachee High School in Barrow County, about 50 miles (80 kilometers) northeast of Atlanta.

It was not immediately clear what prompted the lockdown. Calls and messages to the Barrow County Sheriff’s Office and the school were not immediately returned.

“I have directed all available state resources to respond to the incident at Apalachee High School and urge all Georgians to join my family in praying for the safety of those in our classrooms, both in Barrow County and across the state,” Georgia Gov. Brian Kemp said in a statement.

“We will continue to work with local, state, and federal partners as we gather information and further respond to this situation,” Kemp added.

In a statement, the FBI’s Atlanta office said: “FBI Atlanta is aware of the current situation at Apalachee High School in Barrow County. Our agents are on scene coordinating with and supporting local law enforcement.”