New York City Mayor Bill de Blasio on Wednesday said President Trump needs to take the lead in an effort to stop violent political rhetoric, after explosives were sent to Hillary Clinton, Barack Obama, CNN, George Soros, and others on the Left.

Speaking to reporters in New York, de Blasio didn't blame Trump for the incidents that police say are connected, but indicated that Trump needs to lead.

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"Unfortunately, this atmosphere of hatred is contributing to the choices people are making to turn to violence. There's no question about it," the Democratic mayor said.

"And the way to stop that is to turn back the other way, to bring down the temperature, to end any messages about the use of violence against people we disagree with, and that has to start at the top," he said.

De Blasio was asked if he had any message to Trump specifically, given that the targets of the bomb threats are all his political opponents. But de Blasio said members of both parties need to cool down their language.

"To all public officials of all partisan affiliations: don't encourage violence," he said. "Don't encourage hatred, don't encourage attacks on media."

"You can disagree, but you have to show respect for people and air your disagreements peacefully," he said.

Democrats have said Trump has encouraged violence, in particular against the press, by mocking reporters at his rallies and calling the media "fake news" and un-American.

But Republicans have said Democrats have done similar things. Clinton has said Democrats shouldn't be civil until they win control of the government again, and former Attorney General Eric Holder said recently that when Republicans go low, "we kick them."