NASHVILLE (AP) — An ammonia leak at a Coca-Cola plant in Nashville early Monday forced workers to evacuate for several hours until it was contained.

The leak was called in just before 3 a.m. Reporters on the scene with WKRN say the fire chief gave the all-clear call by 5:30 a.m.

Firefighters and hazardous materials crews responded and about 20 people were helped to safety, with no reported injuries.

Investigators haven't revealed what caused the leak at the Berry Hill factory, which is near the Nashville fairgrounds.