Robert De Niro, one of the targets of a spate of suspicious packages being sent in the post, has said "votes are more powerful than bombs".
The Oscar-winning actor is urging people to vote in the forthcoming US midterm elections on 6 November.
He is one of a number of Donald Trump critics to receive such a package.
"There's something more powerful than bombs," he said, "and that's your vote. People MUST vote!
"I thank God no one's been hurt, and I thank the brave and resourceful security and law enforcement people for protecting us."
A bomb squad unit removed a package that was addressed to the Hollywood actor at his office in Manhattan.
De Niro, 75, has been an outspoken critic of Mr Trump, declaring at one stage that he would like to punch the president in the face.
The actor, who won an Oscar for his starring role in the boxing movie Raging Bull, received a standing ovation at the Tony Awards in June when he punched his fists in the air and said: "I'm going to say one thing – f*** Trump!"
The US president responded by tweeting: "Robert De Niro, a very Low IQ individual, has received too many shots to the head by real boxers in movies.
"I watched him last night and truly believe he may be 'punch-drunk'."
De Niro's statement was released as US police were investigating two further suspicious packages, sent to Democrat senator Cory Booker and former director of national intelligence, James Clapper.
Mr Clapper's was addressed care of CNN.
He told the news channel, where he works as an analyst, that the incidents were "serious" and "definitely domestic terrorism".
He added that the packages would "not silence the Trump administration's critics".
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The latest developments come after glass-filled devices were sent to leading Democrat politicians Barack Obama, Hillary Clinton and former Vice President Joe Biden.
Officials previously described the devices as "crude" but said they were treating them as if they were "viable" explosives.