PARRIS ISLAND, S.C. (AP) — The Marine Corps has punished at least eight drill instructors amid allegations of hazing and abuse at a training center in Parris Island, South Carolina.

Marine officials and documents obtained by The Washington Post say investigators found multiple incidents of female drill instructors abusing female recruits in the 4th Recruit Training Battalion.

The documents say investigations into the allegations were launched when the corps began considering more fully integrating male and female recruit training.

One instructor is accused of shoving a recruit and chipping her tooth, another is accused of forcing a recruit to wear "feces soiled underwear" on her head. The latter instructor denied that.

Spokesman Capt. Bryan McDonnell says instructors received punishments "relative to substantiated allegations." He says some officers who oversaw the instructors were also punished.