Four people have been killed and at least nine others injured in a shooting at a high school in the US state of Georgia.

A suspect was arrested as officers swarmed the campus and students rushed for shelter in a football stadium.

The suspect is in custody, the Barrow County Sheriff’s Office said in a statement.

Shortly before 10.30am “officers from multiple law enforcement agencies and Fire/EMS personnel were dispatched to the high school in reference to a reported active shooting”, the sheriff’s office statement said.

“Casualties have been reported, however, details on the number or their conditions is not available at this time,” the statement added.

Helicopter video from WSB-TV showed dozens of police and emergency vehicles surrounding Apalachee High School in Barrow County, about 50 miles (80km) north-east of Atlanta.

“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 governor 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,” Mr 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 co-ordinating with and supporting local law enforcement.”

Calls and messages to the Barrow County Sheriff’s Office and the school were not immediately returned.

Apalachee High School has about 1,900 students, according to records from Georgia education officials. It became Barrow County’s second largest public high school when it opened in 2000, according to the Barrow County School System. It is named after the Apalachee River on the southern edge of Barrow County.