The FBI confirmed Friday it had recovered a suspicious package addressed to Tom Steyer. The bureau said the package was similar to the ones intercepted last week.
Steyer, a billionaire hedge fund manager-turned political activist, was also targeted in the initial wave of packages, which the FBI has attributed to Cesar Sayoc.
Authorities arrested Sayoc last Friday, and charged him with interstate transport of explosives, mailing of explosives and making threats against former presidents, among other things.
At the time of Sayoc's arrest last week, the bureau warned other packages could still be in transit.
Additional reporting by Newsy affiliate CNN.