A restroom at a Wal-Mart in eastern Indiana has been closed indefinitely after an employee discovered a working meth lab inside . State police say a Wal-Mart employee alerted police after seeing a man he described as suspicious enter the restroom about 11:30 pm Thursday with a backpack and then leave without it . Police were called , and determined that inside the backpack were items that constituted a miniature meth lab , with chemicals used to 'cook ' the drug were being mixed in containers . State police say people who make methamphetamine are leaving 'the deadly explosive chemicals in public places to return later to get the finished product , ' rather than risk explosions and contamination at their own homes . Scroll down for video . Scene : An employee of the Walmart at 1501 E. 29th St. in Muncie alerted police officers to a backpack that had been left in this restroom , which was being used to mix dangerous chemicals to make methamphetamine . The incident occurred at the Wal-Mart in Muncie , Indianapolis , late on Thursday night . The discovery of such 'labs ' are becoming routine for authorities . The fastest way to make meth is referred to as 'shake and bake ' , where the chemicals are mixed in two liter bottles , and later cooked in the oven until it crystallizes . However mixing the chemicals runs a huge risk of explosion , with the blast of one bottle capable of killing someone . The Star Press reports that members of a state police meth suppression team removed the dangerous chemicals . Delaware County Health Department inspectors closed the restroom and a nearby women 's restroom until they could be 'decontaminated ' by a professional cleaning company . An investigation into who left the backpack in the restroom is now under way . Brian Nick , director of National Media Relations for Walmart , said the store 's surveillance video was being provided to police for that probe . Dangerous : The fastest way to make meth is referred to as 'shake and bake ' , where the chemicals are mixed in two liter bottles , and later cooked in the oven until it crystallizes . This is a file photo .
Police were called to a Wal-mart in Muncie , Indiana , at 11.30 pm Thursday . A man had left a backpack inside the restroom . Inside the pack were containers filled with mixed chemicals to make meth . Mixing the chemicals runs a high risk of explosion . More people are setting up makeshift 'labs ' to stop explosions at home . Police removed the chemicals and now trying to track down the suspect .