Authorities say a threatening letter containing an unidentified white powder was sent to a John McCain campaign office in the Denver suburb of Centennial, and a similar letter was sent to a McCain office in Manchester, N.H.
A hazardous materials team was trying to determine if the powder found in Colorado is harmful.
It wasn't immediately known if the New Hampshire letter also contained a powder, said Jeff Sadosky, a spokesman with McCain's national campaign office in Arlington, Va.
Andy Lyon of Parker South Metro Fire Rescue Authority said a worker at the Colorado office discovered the power after opening the letter Thursday afternoon.
Lyon said no injuries have been reported.
Seven people drove themselves to Sky Ridge Medical Center, but none showed any symptoms of exposure to a toxic substance, said hospital spokeswoman Linda Watson.
Postal Inspector Jo Jan Henderson said agents from her office are on the scene.
Officials with the FBI, Secret Service and the Arapahoe County Sheriff's Department did not immediately return telephone calls.
The threat came four days before the Democratic National Convention opens in Denver.
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.
With the recent suicide of 2001 anthrax attacks suspect Dr. Bruce Ivins, awareness of the such dangers have been recently heightened.
Andy Lyon of Parker South Metro Fire Rescue Authority said a worker at the office discovered the power after opening the letter Thursday afternoon.
Lyon said no injuries have been reported but some people may have gone to hospitals on their own.
Postal Inspector Jo Jan Henderson said agents from her office are the scene.
Officials with the FBI, Secret Service, Arapahoe County Sheriff's Department and McCain's Colorado campaign did not immediately return calls.
The threat came four days before the Democratic National Convention opens in Denver.
