The FBI says that threatening letters containing a white powder have been sent to Chase bank locations in seven states as well as Washington, D.C., the Denver Post reports Tuesday.
The FBI says so far tests show the powder to be harmless, but more testing is continuing.
The Post says eight Chase outlets around Denver received the letters, causing at least some of those locations Monday to be evacuated.
Authorities say besides Colorado and Oklahoma, the letters were sent to Chase branches or credit-card facilities in New York, New Jersey, Texas, Ohio and Illinois, as well as Washington, D.C.
One letter was cut open by a machine at a Chase credit card facility in Elgin, Ill., causing the powder to fly around the mail room, the Post quotes police as saying. Chase bank is part of JPMorgan Chase & Co.