Crude pipe bombs addressed to Hillary Clinton and former President Barack Obama appear to be sent from the same source that mailed an explosive device to CNN headquarters in New York, according to the NYPD.
Suspicious packages addressed to actor Robert De Niro and former Vice President Joe Biden were intercepted one day later, and investigators said they were similar in nature.
Biden is scheduled to speak at the University at Buffalo.
A package to Gov. Andrew Cuomo's office was flagged, but the NYPD later deemed it non-threatening — that it contained a flash drive. Cuomo later announced he would be doubling security at infrastructure points around New York City in the wake of the findings.
"Out of an abundance of caution, I am deploying additional National Guard soldiers and directing State law enforcement to double security at vital transportation assets across New York," Cuomo said in a tweet. "New Yorkers have never succumbed to fear or intimidation, and today will be no different."
NY1 was quickly on the scene after CNN's newsroom was evacuated.
Police in Westchester County say a suspicious device was found late Tuesday night en route to the Clintons' Chappaqua home. Sources tell NY1 that the package, described as an IED, was discovered around 1 a.m. during a routine mail screening.
This comes the same week a bomb was discovered outside the Westchester home of billionaire George Soros. The NYPD's chief of counterterrorism said that it, along with the other devices, appeared to be a crude pipe bomb from the same source.
A package intended for Attorney General Eric Holder ended up at a Florida office of Democratic Rep. Debbie Wasserman Schultz, whose return address was on it. Two additional packages which were intercepted were addressed to California Rep. Maxine Waters.
No explosions or injuries were initially reported.