Law enforcement officials converged on a Grand Forks, North Dakota, Wal-Mart Sunday night after receiving reports of a gunman at the store.
The threat appears to have been a prank, however, WDAY reports.
No gunman was found in the store, which reopened at 5:30 a.m. Monday, the Grand Forks Herald says.
This is the same Wal-Mart that was the site of a fatal shooting back in May.
The manager of the Wal-Mart store called police before 9 p.m. Sunday saying an employee was on the phone with a man claiming to be inside the store, armed with a gun and holding two people hostage, WCCO says. The caller demanded $2,000 cash and threatened to harm the hostages, the Grand Forks Herald adds.
Police and SWAT officials responded, setting up a perimeter around the store and evacuating the 100 or so shoppers who were inside onto buses while police investigated, reports note.
Lt. Bill Macki told the Grand Forks Herald Monday that "it does not appear an actual threat was present within the store."
Macki told WDAY that he's sure the employees are shaken up, noting this isn't something they ever wanted to deal with, "let alone two very serious incidents happen[ing] within a short time frame."
Police were called to the same store back in May when a gunman killed one Wal-Mart employee and injured another before taking his own life inside the store.
Police said the gunman – Marcell Willis, a 21-year-old airman who was stationed at the nearby Air Force base – was drunk at the time of the shooting. Officials are still investigating the case, but note they haven't found an apparent motive for the shooting.
The store was closed for two days following the shooting.
In June 2013, the store was also evacuated after a bomb threat. That report turned out to be a hoax, the Grand Forks Herald says.
Although investigators believe there was no real threat associated to Sunday's incident, they do want to find out who made the phone call. Anyone with information about the incident, including who the caller may be, is asked to contact police at 701-787-8000.