A package resembling those allegedly sent by Cesar Sayoc was recovered Thursday and was addressed to Democratic billionaire Tom Steyer, the FBI tweeted Friday.
"The FBI has confirmed a package was recovered last night in California, similar in appearance to the others, addressed to Tom Steyer," the FBI said in its tweet.
Steyer's organization, The Next Generation, was "notified late last night" by USPS security, who said they had called the FBI and confirmed it was a suspicious package, according to Aleigha Cavalaier, NextGen's communications director.
"They also told us that they suspected (it) was from the same guy, but it was mailed to a different address," Cavalaier said.
CNN previously reported on a mail bomb allegedly sent by Sayoc to Steyer last week.
Steyer thanked law enforcement and the U.S. Postal Service for their support in a statement Friday, stressing that his organization would not be intimidated by the packages.
"These threats are not isolated but are a part of a larger assault on the norms that uphold our democracy," Steyer said in the statement. "We will not relent as we push for the broadest possible democracy and a life of dignity and respect for every American. We are more motivated than ever this Election Day to secure victories for representatives who will uphold the values of democracy rather than assault them for political convenience."
Sayoc, a 56-year-old Florida man, was arrested last Friday in connection with 13 explosive devices mailed around the country to prominent Democrats and CNN, federal authorities said.
Police in Burlingame, California, responded last week to a postal facility that had received a suspicious package addressed to Steyer. Authorities believe that first package was from Sayoc, according to multiple law enforcement officials.
This second delivery to Steyer brings the total number of similar-looking suspicious packages sent to Democratic political figures and CNN to 15.
Steyer, a billionaire philanthropist who has escalated his political spending in the wake of Trump's election, has financed a high-profile campaign for the President's impeachment. Steyer has used a series of national ad campaigns and town halls through his "Need to Impeach" organization to push his message. He had also pledged to spend up to $120 million in the 2018 midterms.
Steyer responded to the first suspicious package by calling for Trump's impeachment, his long-standing rallying cry, to counter "a systematic attack on our democracy."
"We're thankful that everyone we work with is safe," he tweeted last Friday after the first bomb was discovered. "We are seeing a systematic attack on our democracy that extends much further than just one isolated terrorist in Florida. That's why we are running an impeachment petition to end the culture of lawlessness in our country.
Steyer also said last Friday on CNN's "Erin Burnett OutFront" that while he does not "think there's any direct link" between Trump and the bombs, the President's rhetoric "incites people's most emotional and violent feelings."
"What Mr. Trump has done is create an atmosphere that condones violence, that actually incites people's most emotional and violent feelings and creates an atmosphere where people feel free to live out ... that kind of behavior and those kinds of feelings," he told CNN's Kate Bolduan.