NEW YORK (AFP, REUTERS) - At least six people died and another nine were injured on Thursday (Jan 28) in a liquid nitrogen leak at a food-processing plant near the US city of Atlanta, police said.

Five people died at the plant before they could be taken to hospital, while one person died in the emergency room, police from Gainesville, Georgia, told reporters, adding that 10 people were transported to hospital.

Three people were in critical care.

The leak did not cause an explosion, and its cause - which is still unknown - remains under investigation, they said.

The accident occurred at 10am (11pm Singapore time) in a specialised poultry processing plant, Prime Pak Foods, located in Hall County in the southeastern US state.

Officials said that three Gainesville firefighters and one firefighter from Hall County were among those taken to hospital.

At least 130 other people were taken from the plant to gather at a nearby church to be medically evaluated, police said.

Students in nearby schools were temporarily confined to their classrooms as initial reports suggested there had been a chemical explosion.