Two campaign offices of John McCain—one in a Denver suburb, the other in New Hampshire—were shut down today after they received threatening letters with an unidentified white powder, authorities say. No injuries have been reported, and staffers underwent medical checkups as a precaution. A government official said investigators suspect the Denver letter was sent by an inmate as a hoax.
It's not clear if the letters are related, but the one sent to Manchester, NH, had a return address of Denver. The city is under high alert because the Democratic National Convention is just days away. Authorities did not disclose what the letters said, and tests on the powder were still under way. No employees in either office have shown any troubling symptoms.