WASHINGTON -

A senior Air Force commander says 31 female victims have been identified so far in a widening sex scandal that has rocked the service's training command at Lackland Air Force Base.

Gen. Edward Rice, commander of the Air Education and Training Command, tells Pentagon reporters that a dozen male instructors are under investigation, and that nine of them are from the same unit -- the 331st Training Squadron.

Rice says the Air Force believes this is not a problem endemic to the nine training squadrons, and that it appears to be localized. He says the sexual misconduct occurred over the past two and one-half years, but the first woman came forward only a year ago.

The Air Force has launched an independent investigation across all training units.