Walmart shut down after portable meth lab is discovered in shoplifter's purse

Detective Inspector Greg Cramer points to a bag of crystal meth pills confiscated on August 19, 2010, in Auckland, New Zealand.

Employees of a Walmart near St. Louis, Missouri, got a little more than they bargained for when they stopped a shopper who they suspected was shoplifting and discovered a "mobile methamphetamine lab" in her purse.

According to the St. Louis Post-Dispatch, after the female culprit shoplifted an item that was unrelated to meth-making, she was confronted by employees. Store security and police then searched her purse, finding a 20-ounce bottle containing methamphetamine.

The Walmart store was evacuated for almost three hours, Reuters reported.

Deputy Chief Dan Furrer with the Mehlville Fire Protection District said that the "shake and bake" lab was seized without incident.

"It had the potential to be flammable or blow up at any time," St. Louis Police Lt. Mark Cox said. No one was reported injured and no further harmful substances were discovered inside the store, which reopened later in the evening.

Drug charges for the woman and a male companion are pending, CBS News reported.