The package bombs sent to prominent Democrats have touched off a bitter war of words in an already-combustible political environment just days before the midterms, even as the investigation continues and law enforcement officers remain on the hunt for more explosive parcels.

Former Vice President Joe Biden was the latest apparent target, with the FBI confirming two suspicious packages similar to the ones that triggered the original security scare were addressed to him in Delaware, along with one to actor Robert De Niro. A suspect has not been identified and presumably remains at large.

Attorney General Jeff Sessions was being briefed Thursday morning on the latest updates in the FBI investigation.

On the sidelines, top political leaders sparred over whether overheated political rhetoric – and whose – was to blame.

After President Trump called Wednesday for unity, Senate Minority Leader Chuck Schumer and House Minority Leader Nancy Pelosi said the president’s “words ring hollow until he reverses his statements that condone acts of violence.”

They noted he recently praised a congressman who body-slammed a reporter and often calls media outlets “the enemy of the people.”

While Trump used a subdued tone in the immediate aftermath of the package bombs’ discovery, he tweeted Thursday morning that the media are also fanning the flames.

“A very big part of the Anger we see today in our society is caused by the purposely false and inaccurate reporting of the Mainstream Media that I refer to as Fake News. It has gotten so bad and hateful that it is beyond description. Mainstream Media must clean up its act, FAST!” he tweeted.

Former CIA Director John Brennan – the target of one of the package bombs, which was sent to CNN’s office in New York City and led to a dramatic evacuation Wednesday of the Time Warner Center – fired back.

“Stop blaming others. Look in the mirror. Your inflammatory rhetoric, insults, lies, & encouragement of physical violence are disgraceful. Clean up your act....try to act Presidential. The American people deserve much better. BTW, your critics will not be intimidated into silence,” Brennan tweeted.

White House Press Secretary Sarah Sanders, asked on “Fox & Friends” about such criticism, stressed that only the bomber is to blame.

“The president could not have been more presidential yesterday,” she said, adding that the individual sending these packages “is ultimately the person that is responsible.”

As for Brennan, she said only that administration officials “don’t support the type of activity that he is engaged in and don’t think it’s becoming of somebody that is a former director” of the CIA.

Brennan is an NBC analyst, despite the package being sent to him via the CNN office.

He was one of several prominent current and former officials – all Democrats – who were sent what authorities described as pipe bombs in the mail. They did not detonate or reach their intended targets.

Similar packages were addressed to former President Barack Obama, former Secretary of State Hillary Clinton, liberal billionaire George Soros and Rep. Maxine Waters, D-Calif. Another package was apparently sent to former Attorney General Eric Holder with the wrong address and then sent back to the return address, which was a Florida office for Rep. Debbie Wasserman Schultz, D-Fla.

Waters, who has faced past Republican criticism for her calls to confront Trump administration officials in public spaces, said Trump should “take responsibility” for the latest violence.

In a video for Blavity, Waters said Trump is “encouraging people in his own way to be violent, or to be racist.”

Fox News’ Jake Gibson contributed to this report.