New Orleans Police turned up empty in their search Saturday for a gunman who they say entered a Gentilly Walmart store shortly after it opened, causing customers and employees to flee in fear and a SWAT team to descend on the scene.

The store was closed and Chef Menteur Highway was blocked off in both directions for several hours Saturday morning as officers searched the store and -- with guns drawn -- the cars in its parking lot for a person who witnesses said entered Walmart wearing a hooded shirt and a covering over his or her face.

Police said no shots were fired inside the store and no one was injured or taken hostage during the incident. It is not clear if the gunman attempted to rob the store.

Walmart reopened later in the day after employees were questioned. Several declined to speak to a reporter, citing a warning from managers that they would be fired if they did. The Gentilly Walmart employs about 300 people, said Clint Sampson, who manages another Walmart store and was called to the scene to assist the Gentilly store with reopening. Sampson did not know how many people were working Saturday morning.

Robert Silva had gone into the store to buy water before heading in to his 6:30 a.m. work shift in the French Quarter. As he stood at the check out counter at about 6:10 a.m., he “noticed in my peripheral vision to the right was a man in a hoodie.”

“I saw something in his hand,” Silva said. “I didn’t pay too much attention, but the ladies who work there came from around the corner and said there is a man with a gun. That’s when the manager say ‘Everybody stay calm and walk out of the store.’”

Silva said he and others walked out and began dialing 911.

By the time police arrived on the scene most of the people inside the store had already fled through the stores main entrance and a back door, Silva said.

Last month, a man wearing a Walmart uniform robbed the same store of $120,000 in case, police said. The suspect fled into a waiting car. He is still at large.