A suspicious letter containing an oily substance that was sent to the Phoenix office of Sen. Jeff Flake caused a brief scare Wednesday before the mail was tested and found to be harmless.
The panic occurred as the country is on edge after the explosions in Boston and preliminary tests that showed poisonous ricin was found in two letters sent to President Obama and a Mississippi senator.
Authorities evacuated part of Flake's office Wednesday after staff for the Republican senator came across mail that was stained with the oily substance. But Postal Inspection Service spokesman Keith Moore said the mail was tested and deemed harmless.
It's not immediately clear what the oily substance was.
"There was nothing of danger found in the letter," Moore said.
Emergency crews in hazardous materials gear rushed to the scene and cleared out parts of the building, in the trendy Biltmore neighborhood of Phoenix. Sen. John McCain's office is across the street, and staff there was told to be on the lookout for anything suspicious as authorities investigated.
The exact number of suspicious letters sent to Flake was unclear. Moore indicated it was one letter, but other agencies said there were two suspicious envelopes.
Flake spokeswoman Genevieve Rozansky said in a statement that all staff members were safe and that the senator's office had no details on the suspicious mail. Flake was in Washington on Wednesday.
Flake was elected to the Senate last year after serving in the U.S. House. He is among a bipartisan group of U.S. senators who worked on an immigration bill that was formally introduced in the Senate earlier Wednesday.