A security guard on the lookout for shoplifters searched two teenage girls as they left a Manhattan lingerie shop Thursday afternoon, and discovered one of them was carrying what appeared to be a fetus in her bag, police said.

Both girls are 17. One was hospitalized and the other was being questioned at a police precinct, authorities said. The medical examiner's office was performing an autopsy on the apparent human remains found inside the bag.

The girls were shopping at a Victoria's Secret lingerie store in midtown Manhattan, said police, who were called to the scene. Authorities are trying to determine if one girl gave birth in the store, or if she had been carrying the remains with her. She apparently told detectives she delivered a day earlier, but didn't know what to do with the remains, police said. It wasn't clear whether the fetus was alive or dead when delivered.

Victoria's Secret is owned by Columbus, Ohio-based Limited Brands. A spokeswoman for the company referred calls to the NYPD.

Police are also investigating whether the girls had actually stolen anything from the store. It wasn't clear whether they will face criminal charges.

The store remained open for business and was filled with customers from around world. An NYPD crime scene unit spent a few hours gathering evidence inside the store before leaving shortly before 5 p.m. A single marked police car remained at the front entrance that faces Herald Square at 34th Street.