Even as authorities were uncovering new packages that possibly carried explosive devices addressed to a Democratic lawmaker in Congress, President Donald Trump told a campaign rally in Wisconsin that a more civil political atmosphere is needed in America, pointedly calling on the news media to end what the President labeled an 'endless hostility' and 'negative attacks.'

"The federal government is conducting an aggressive investigation, and we will find those responsible, and we will bring them to justice hopefully very quickly," the President said in a campaign stop in Mosinee, Wisconsin.

Along the way, Mr. Trump though had pointed words for political opponents and the news media, seemingly making the point that they had set the stage for an explosive political atmosphere in 2018.

"Those engaged in the political arena must stop treating political opponents as morally defective," said the President, who has often belittled and mocked his critics with taunts and nicknames.

Hours after a pipe bomb was delivered to the offices of CNN in New York, the President made clear that he believed the news media was a prime cause behind current political divisions in America.

"The media also has a responsibility to set a civil tone, and to stop the endless hostility and constant negative, and often times false attacks and stories," the President said to cheers. "They've got to stop."

By the time the President finished his over one hour speech in Wisconsin, the FBI was telling news organizations that two more packages - both addressed to Rep. Maxine Waters (D-CA) - had been found in a Los Angeles area mail facility.

"The packages were affixed with computer-printed address labels and six Forever stamps," the FBI reported, noting they contained "potentially destructive devices" described as pipe bombs.

Earlier in the day, a package addressed to Rep. Waters had been stopped at an off-site mail processing facility outside of Washington, which is used to go through mail sent to Capitol Hill.

That raised to seven the number of mail bombs discovered in about a twelve hour period, sent to former President Barack Obama, former Secretary of State Hillary Clinton, Obama Attorney General Eric Holder, and then three directed at Rep. Waters, who has been a frequent critic of the President.

"I unequivocally condemn any and all acts of violence and terror," Waters said in a written statement.

One of the packages - sent to Holder - was returned through the mail to the district office of Rep. Debbie Wasserman Schultz (D-FL), a former head of the Democratic National Committee.

It wasn't immediately clear if the seven packages represented all of the threats - or if there were more mail bombs in the postal system, as members of both parties denounced the developing events.

"There is absolutely no place for violence or threats of violence against public officials, their staffs, or the media," said Rep. Austin Scott (R-GA).

"Americans must stand together against these awful acts of terror," said Rep. Ted Deutch (D-FL).