A man called the Inland Northwest Bank at 500 W. Francis Ave. and demanded a large sum of money just before noon Thursday.
The man threatened to harm local school children if he did not receive the money within a certain time frame, Spokane police said.
Police notified area schools and told staff members to be cautious of anything suspicious looking. Administrators checked the perimeters of all school buildings in the area but found nothing.
Officers detained a man and a woman near 13th Avenue and Arthur Street around 2 p.m., police said.
The man was booked into Spokane County Jail on unrelated warrants. The woman has since been released.
A search warrant will be executed at the residence on 13th Avenue and Arthur Street, police said.
The names of the suspects have not been released.