A suspicious package similar to those believed to have been sent to Barack Obama, Hillary Clinton and CNN has reportedly been found at a New York restaurant owned by Robert De Niro.
The New York Police Department (NYPD) said it had safety removed the suspect item, which had been delivered to an address in Manhattan's Tribeca neighbourhood.
NBC's New York affiliate, News 4, reported that the package was sent to a commercial building in Greenwich Street, which houses the Tribeca Grill restaurant owned by De Niro.
The sender of the packages appears to be targeting high-profile critics of Donald Trump - and actor De Niro has publicly attacked the president on a number of occasions.
Police said early investigations appeared to suggest the same sender was responsible for the latest parcel.
An FBI-led Joint Terrorism Task Force of federal, state and local law enforcement agencies “will continue to work to identity and arrest whosoever is responsible for sending these packages,” FBI Director Christopher Wray said in a statement.
Investigators are also thought to be trying to track down another suspicious parcel they believe was addressed to Mr Obama's vice president, Joe Biden, that never reached its intended destination.
None of the eight devices discovered so far have detonated, but some top Democrats have described the attempted bombings as a symptom of the combative brand of political rhetoric deployed by Mr Trump and his supporters.
Several politicians across party lines, including senate majority leader Mitch McConnell and New York mayor Bill de Blasio, have branded incidents an act of terrorism.
The president has also condemned the attack, pledging his administration would conduct an “aggressive investigation” to identify the perpetrator.
“Any acts or threats of political violence are an attack on our democracy itself,” he told a rally in Wisconsin on Wednesday. “We want all sides to come together in peace and harmony.”
However, Mr Trump also said the media had a responsibility “to stop the endless hostility and constant negative and oftentimes false attacks and stories.”
The first package arrived on Monday at the upstate New York address of Mr Soros, an investor and philanthropist whose liberal values have made him the target of numerous right-wing conspiracy theories.
The parcel consisted of a manila envelope with a bubble-wrap interior containing what officials described as a “potentially destructive device”.
Investigators have said each of the devices found since have been similar in appearance, all bearing computer-printed addresses and six “forever” stamps.
Additional reporting by Reuters
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies