A caller told a Bismarck police shift commander he had planted bombs at both Wal-Mart locations, but searches of the businesses turned up nothing.
Sgt. Mark Buschena said the call came in at 2:12 a.m. Monday. The caller told the shift commander he had planted bombs at both Wal-Marts, then hung up the phone, Buschena said.
He would not comment on whether police were able to trace the call.
Officers went to both Wal-Marts, advised managers of the situation, evacuated the stores and searched the areas, Buschena said.
He said nothing was found at the north location, and employees and customers were allowed to re-enter the building at 3:32 a.m. At the south location, officers found a suspicious package, but it was later determined to be merchandise. A police report did not say what time people were allowed back into the south Wal-Mart, Buschena said.
The threat remains under investigation. Buschena said police do not have a suspect.