Fire officials say a mysterious odor that prompted the evacuation of a Wal-Mart store in West Bend, Wis., Friday morning posed no danger.

Fire officials allowed the store to re-open hours after the emergency evacuation, a spokesman for the discount retail chain told the Milwaukee Journal Sentinel.

"The decision to evacuate the (West Bend) store was made to protect the safety of our customers and employees and it was a precaution," Wal-mart spokesman Dan Fogleman of Bentonville, Ark., said.

Fogleman said the mysterious smell may have been sewer gas, but added an investigation was underway to determine its origin.

Only a few customers were in the West Bend store at the time of the evacuation, along with nearly 30 employees, the Journal Sentinel said.

The incident came less that a day after nearly 50 people fell ill at a Wal-Mart in Germantown, Wis., the newspaper said.