At least one person is dead and four others injured after a gunman opened fire at a medical facility in Atlanta, Georgia, USA.

Footage from the scene shows emergency crews, a large police presence and two victims being taken to ambulances on stretchers.

The gunman, who was identified as 24-year-old Deion Patterson, was arrested after an eight-hour long manhunt.

The Atlanta Police Department responded to a report of an active shooter at Northside Medical Midtown around 12:30 pm on Wednesday.

Those in the area were advised to secure their buildings and shelter in place.

Atlanta Police Deputy Chief Charles Hampton said the gunman opened fire inside the medical center before fleeing the scene on foot.

He was spotted by an undercover police officer in the Cobb County area after hijacking a vehicle and taken into custody.

Four people were transported to Grady Memorial Hospital with three of them arriving in critical condition.

One person was pronounced dead at the scene, police said.