SMYRNA -- At least three people were injured, one of them critically, during an explosion Monday at a Cobb County gun facility, authorities said.

The accident occurred shortly before 11 a.m. at the Glock gun factory, located in the 6000 block of Highlands Parkway.

At least one person was flown by helicopter and two others taken by ambulance to Grady Memorial Hospital for treatment. A hospital spokeswoman said one man was in critical condition, a woman was in stable condition and the third man was in good condition. All three suffered burns during the incident.

Officials said the three people were in the same room and were working in the gun test firing area when the blast occurred.

According to the company's Web site, the firm, best known for its pistol, has developed and manufacturers at least 37 models of the firearm. It was not immediately clear what model, if any, is made at the Smyrna facility.

More details to come.