ALBANY – Gov. Andrew Cuomo said a "device" was sent to his Manhattan office Wednesday amid suspicious packages being sent to Hillary Clinton, Barack Obama and CNN's Manhattan office.

It turned out the "device" was a letter and USB flash drive, according to the New York City Police Department.

"The earlier suspicious package at Governor Cuomo’s office in midtown has been cleared by NYPD personnel. It was unrelated. And there was no device of any kind," NYPD spokesman J. Peter Donald wrote on Twitter.

His office was deemed safe, police said.

Cuomo spokesman Rich Azzopardi said: "A preliminary investigation on the package at Governor Cuomo's office shows it is computer files on the hate group, The Proud Boys, who recently appeared in New York."

As he was attending a briefing with law enforcement officials about explosive devices sent to other high-profile officials and CNN, Cuomo's top aide, Melissa DeRosa, walked up to the governor, said something in his ear and showed him something.

She was showing Cuomo an image of the envelope, according to Azzopardi, who said NYPD Commissioner James O'Neill had alerted the governor to the suspicious package before the briefing began.

Moments later, Cuomo announced live on national television: "A device has been sent to my office in Manhattan, which we were just informed about, and that device is also being handled."

But within an hour, NYPD said there was nothing unsafe found.

When he was initially asked outside his office about the reports of no suspicious devices found at his office, Cuomo said it was too soon to say.

"It is still being investigated, and I don’t want to comment on it until the investigation is complete," Cuomo told reporters.

The Secret Service said at the briefing that packages addressed to Hillary Clinton and Obama were intercepted by law enforcement officials, including earlier this morning at Clinton's Chappaqua home in Westchester.

Police swarmed CNN earlier Wednesday with a bomb squad in Manhattan, and the newsroom was evacuated.

NYPD said an envelope with white powder was found at the CNN offices.

Cuomo and New York Mayor Bill de Blasio said the incidents were acts of terrorism.

"We will not be intimidated, and we will bring these perpetrators to justice," O'Neill said.

De Blasio said there were no other credible threats in the city, and initially Cuomo's spokesman dismissed an earlier report that something was sent to Cuomo's office.

Azzopardi said the package sent to Cuomo's office was discovered after the initial ABC report Wednesday morning.