FORT STEWART, Ga. (AP) — A sergeant shot five soldiers Wednesday at one the country’s largest Army bases before he was quickly tackled by other Fort Stewart troops, forcing a brief lockdown, officials said.

Few details were immediately available about what led to the gunfire, but officials said the shooter was Sgt. Quornelius Radford, 28, who used a personal handgun, not a military firearm.

Radford opened fire where he worked but officials wouldn’t speculate about a motive, authorities said.

The injured soldiers are stable and expected to recover, said Brig Gen. John Lubas. The soldiers who tackled Radford helped ensure his arrest, said Lubas, who commands the 3rd Infantry Division.

“These soldiers, without a doubt, prevented further casualties or wounded,” he said.

This latest act of violence on a U.S. military installation — sites that are supposed to be among the most secure in the country — again raised concerns about safety and security within the armed forces’ own walls.

The Army said it's investigating the shooting. There were still many unanswered questions, including the scope of the injuries and the shooter's motive.

The injured were taken to the hospital and three underwent surgery, officials said.

A telephone number listed for Radford in public records rang unanswered.

Army records released to The Associated Press show that Radford enlisted in January 2018. He worked as a supply sergeant and has not been deployed.

Radford faced an Aug. 20 hearing in Hinesville, a small town near the base, on accusations of driving under the influence and running a red light just after 1 a.m. on May 18, according to a citation and court filing. He was given a blood test and freed on a $1,818 bond, the documents said.

Attorney Sneh Patel is representing Radford in the traffic case but not the shooting as of Wednesday, he said in an email. He cited attorney-client privilege in declining to comment about any his conversations with Radford.

Law enforcement was sent to the 2nd Armored Brigade Combat Team complex shortly before 11 a.m. The shooter was arrested at 11:35 a.m., officials said.

The lockdown lasted about an hour. After it was lifted, cars began to move through the normal security checkpoint at the fort’s main gate.

The Army’s 2nd Armored Brigade Combat Team was created in 2016 when the service added more than 200 vehicles to an infantry unit of roughly 4,200 soldiers. Also known as the “Spartan Brigade,” the Army has called the unit its “most modern land fighting force.”

Located about 40 miles (64 kilometers) southwest of Savannah, Fort Stewart is the largest Army post east of the Mississippi River by land area. It’s home to thousands of soldiers assigned to the Army’s 3rd Infantry Division and family members.

President Donald Trump called the shooter a “horrible person” in comments to reporters at the White House.

The FBI was at the fort to help investigate, said Deputy Director Dan Bongino.

Among the deadliest acts of violence on U.S. military bases was a 2009 attack. A U.S. Army psychiatrist killed 13 people in a shooting that left more than 30 wounded at Fort Hood, a military installation in Texas.

In 2013, a defense contract worker and former Navy reservist killed 12 people at Washington Navy Yard. He was then killed in a gun battle with police.

In 2014, a soldier opened fire on his fellow service members at Fort Hood, killing three people and wounding more than a dozen others before the gunman killed himself.

In 2019, an aviation student opened fire in a classroom at Naval Air Station Pensacola in Florida, killing three people and injuring another dozen people including two sheriff’s deputies. Just days earlier, a U.S. Navy sailor shot two people to death before killing himself at Pearl Harbor, the Naval station in Hawaii.