New York City’s police commissioner says a package sent to CNN’s offices in New York contained what appeared to be a live explosive and an envelope containing white powder.

At a briefing near Manhattan’s Time Warner Center, Commissioner James O’Neill pledged to bring the perpetrators to justice.

The police department’s top counterterrorism official, John Miller, said the substance was being tested to see if it is dangerous.

New York Gov. Andrew Cuomo said at the briefing that “we will not allow these terrorist thugs to change the way we live our lives.”

The officials said the CNN bomb was crude but operational and was addressed to former CIA Director John Brennan, who appears on air on other broadcast and cable outlets.

CNN was on the air when what sounded like a fire alarm went off. 

Poppy Harlow and Jim Sciutto, who were anchoring at the time, tweeted that a potential explosive device was received and the bomb squad was at the scene.

Earlier in the day, a suspicious package was sent to Barack Obama and an explosive device was sent to Bill and Hillary Clinton. On Monday, a device was sent to billionaire George Soros.

Officials tell the Associated Press the device discovered at CNN Wednesday appeared to be similar to the explosives sent to Obama, Clinton and Soros.

News Channel 8’s White House Correspondent spoke with White House Press Secretary Sarah Huckabee Sanders after the discoveries. She said, “it’s ok to disagree in politics but it’s never ok to take action against another individual.”