Casualties have been reported amid a lockdown at the US Army’s Fort Stewart in Georgia, after a Fort Stewart police spokesperson confirmed “there is an active shooter.”

The nature of the casualties is unclear.

Lt. Col. Angel Tomko, the Fort Stewart Police Department spokesperson, would not provide further details, but the verified Facebook page for Fort Stewart Hunter Army Airfield said, “Casualties have been reported and the situation is ongoing.”

“The installation was locked down at 11:04 a.m. and law enforcement is on the scene at the time,” the post said.

The US Army’s Fort Stewart trains and deploys active and reserve Army units and is home to the 3rd Infantry Division. It is about 40 miles southwest of Savannah, Georgia.

More than 10,000 people – soldiers, family members and Army civilian employees – reside on the post, according to its website.

Agents from the FBI’s Savannah, Georgia, office are responding to Fort Stewart and coordinating with the Army Criminal Investigation Division, according to an FBI Atlanta spokesperson.

Georgia Gov. Brian Kemp said on X he was in “close contact” with law enforcement, saying he was “saddened by today’s tragedy at Ft. Stewart.”

“We are keeping the victims, their families, and all those who answer the call to serve in our hearts and prayers, and we ask that Georgians everywhere do the same.”

This is a developing story and will be updated.

CNN’s Rebekah Riess and Devon Sayers contributed to this report.