A letter that contained a suspicious substance was sent to Sen. Chris Murphy's office in Hartford Thursday, Josh Sorbe, a spokesperson for the senator confirmed.

Sorbe says the letter was intercepted en route.

Murphy's office was informed of the letter by FBI, SAA and Capitol Police. They are working closely with those agencies, along with federal law enforcement.

Murphy has been traveling around the country for the past few days and is currently not in Connecticut.

"Our office is grateful for the investigators involved in this incident, and we intend to continue close coordination as the investigation continues," says Sorbe.

Sen. Richard Blumenthal's office in Hartford also received one of the suspicious letter, according to a spokesperson.

They say that a vigilant staff member identified the suspicious letter while screening the mail. The staff member took immediate steps to isolate it the mail and called Hartford police.