A sergeant in the US Army opened fire at a base in the south-eastern US on Wednesday (Thursday AEST), shooting five soldiers and prompting a brief lockdown at one the country’s largest army installations, officials said.

Few details were immediately available about what led to the gunfire at Fort Stewart in Georgia, but the suspect is an army sergeant, according to a US official. The official was not authorised to publicly discuss details of the investigation and spoke to The Associated Press on condition of anonymity.

The injured soldiers are stable and recovering, said Brigadier-General John Lubas. The army won’t release names pending notification of family members and they won’t speculate on motive, Lieutenant-Colonel Angel Tomko said at a news conference.

Officials identified the shooter as logistics Sergeant Quornelius Radford, 28. A telephone number listed for Radford in public records rang unanswered on Wednesday.

The shooter opened fire at his workplace, officials said. Soldiers in the area who witnessed the shooting “immediately and without hesitation” tackled the shooter, Lubas said.

This latest act of violence on a US 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 condition of the soldiers, the scope of their injuries, the name of the shooter as well as any possible motive.

The injured were treated and then moved to Winn Army Community Hospital, base officials said in a Facebook post, adding there’s no threat to the community.

Law enforcement officers were sent to the 2nd Armoured Brigade Combat Team complex shortly before 11am on Wednesday. The shooter was arrested five minutes later, officials said.

The lockdown lasted about an hour.

Located about 64 kilometre south-west of Savannah, Fort Stewart is the largest Army post east of the Mississippi River. It’s home to thousands of soldiers and family members.