CENTENNIAL, Colo. (AP) -- Authorities say a threatening letter containing an unidentified white powder was sent to a John McCain campaign office in the Denver suburb of Centennial. A hazardous materials team was trying to determine if it is harmful.

Andy Lyon of Parker South Metro Fire Rescue Authority says a worker at the office opened the letter and discovered the powder Thursday afternoon.

Lyon says no injuries have been reported but some people may have gone to hospitals on their own.

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