Investigators in the US state of Georgia are searching for a suspect after a mass shooting at a block party killed two people and injured 35 others in the early hours of Sunday.

The shooting erupted around 01:30 local time in Vienna, a rural community in southern Georgia, during a homecoming celebration linked to Dooly High School. The event was not school-sponsored. A crowd of roughly 1,000 people had gathered for the occasion.

Officials say more than 50 shots were fired into the crowd. Two victims were pronounced dead at the scene, while 25 others were transported to nearby hospitals, some in critical condition. Victims ranged in age from 14 to 51.

The two men killed were aged 20 and 23, according to the Dooly County Coroner. Their bodies were found several blocks from the main shooting scene, on Pine Street.

No arrests have been made. Authorities have not identified a motive.

Anticipating a large gathering, officers from the Dooly County Sheriff's Office were already stationed at both ends of the crowd when the shooting began.

"Some people were reporting fireworks and then someone said somebody been shot," Dooly County Sheriff Craig Peavy told local media. He said officers then moved through the crowd as people fled in different directions, working their way toward the victims.

One witness told a local newspaper that the gunfire sounded "like a machine gun."

Dooly High School issued a statement following the incident. "Our hearts are with the families grieving the loss of loved ones, those who were injured, and everyone affected by this tragedy," the school said.

The Georgia Bureau of Investigation said it would join the inquiry at the request of the Dooly County Sheriff's Office, describing the operation as "active and ongoing." The bureau's Medical Examiner's Office said autopsies would be conducted in both fatality cases.