NEW YORK, U.S. - A neatly wrapped package that arrived at the New York State residence of billionaire philanthropist George Soros on Monday sparked fears and led to a frenzied emergency response.

On Monday afternoon, an employee of the 88-year-old billionaire philanthropist retrieved a package from the mailbox right outside Soros' residence in the town of Bedford in Westchester County.

The employee, who is said to have grown suspicious about the contents of the mysterious package, is said to have immediately alerted authorities in the New York suburb.  

The Town of Bedford Police Department said in a statement that a call received at about 3.45 pm local time (8.45 pm GMT) on Monday reported a suspicious package.

Officers from the Bedford and Westchester County Police Department arrived at the 4-acre property owned by Soros, located at 168 Cantitoe St. in Katonah.

Federal and State law enforcement agencies, including the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives, too dispatched their respective teams that joined the local police officers at the scene.

The Bedford Police Department was quoted as saying in a New York Times report, "An employee of the residence opened the package, revealing what appeared to be an explosive device. The employee placed the package in a wooded area and called the Bedford police."

Investigators reportedly sought the assistance of the Westchester County Police Department's bomb squad, which sent its experts to deal with the device. 

Subsequently, officials said bomb disposal experts had examined the device and "proactively detonated" it in a wooded area nearby.

Officials also confirmed that the Hungarian-American businessman was not at the residence at the time of the incident.

The Bedford Police said that it had escalated the case to the FBI's Joint Terrorism Task Force.

Later in the day, the FBI's New York office confirmed the probe in a statement on Twitter.

The bureau wrote, "We are conducting an investigation at and around a residence in Bedford, NY. There is no threat to public safety, and we have no further comment at this time."

Further, the Bureau of Alcohol, Tobacco, Firearms and Explosives too posted a similar tweet, reassuring residents in the neighbourhood that there was no immediate threat to public safety.

On Tuesday morning, FBI's Joint Terrorism Task Force in New York said in a Twitter post, "We are working with our partners at @NewYorkFBI and @WestCtyPolice conducting an investigation at and around a residence in Bedford, NY. There is no threat to public safety, and we have no further comment at this time."

However, both, the local and Federal authorities have not commented on the nature of the explosive device or the possible motive. 

Investigators have only revealed that the object "appeared to be an explosive," and even refused to confirm if the object was capable of exploding.

A law enforcement official quoted in a report in NBC New York said that device mailed to Soros' residence was similar to a pipe bomb and contained explosive powder.

The official pointed out that no one was injured, adding that authorities detonated the device as a precaution

The world's favourite political target threatened 

The 88-year-old Hungarian-born Jew survived the Holocaust and fled his native country in 1946.

Working different jobs, Soros put himself through the London School of Economics and later moved to New York, where he worked for years, building his fortune by managing a hedge fund. 

Today, the globally renowned billionaire is noted as one of America's biggest philanthropists.

According to figures cited in Forbes Magazine, Soros has donated $32 billion toward philanthropic entities in his entire lifetime.

Soros is the only current member of The Forbes 400 list of richest Americans to have given away 79 percent of his fortune to charity. 

The billionaire has also gained popularity as a political activist and became known as a major political donor in the U.S. during the presidency of George W. Bush.

Claiming that removing Bush from office in 2004 was the "central focus of my life," Soros poured in millions to back John Kerry, but failed in his attempts to deny Bush a second term.

The Democratic megadonor was amongst an early backer of Barack Obama's 2008 presidential campaign.

In the 2016 Presidential Elections, Soros donated over $25 million to Democratic candidate Hillary Clinton and also donated to campaigns by other Democratic candidates. 

Soros has also donated millions to progressive causes and initiatives in the U.S. and spent billions funding human rights projects around the world.

The Open Society Foundation set up by the powerful billionaire, works towards building tolerant democracies.

Soros has also donated to an anti-Brexit campaign and previously described Britain's decision to leave the EU as "an immensely damaging process, harmful to both sides."

However, his left-leaning political involvement has made him a favourite political target for nationalists and populists worldwide.

American right-wing groups have led a hate campaign against Soros and often target him with hate speech and anti-Semitic smears.

In May this year, Roseanne Barr publicly labelled Soros a Nazi in a shocking tweet with a false claim that was shared by the U.S. President Donald Trump's son, Trump Jr.

Soros, who has previously labelled Trump "an imposter," has faced the U.S. President's anger too.

Trump's recently made unproven and bizarre claims, accusing Soros of funding protests against the Supreme Court Judge Brett Kavanaugh and backing the large migrant caravan travelling north from Honduras.

Investigators: The bomb was REAL

The major law enforcement operation that ensued after the explosive device was discovered sparked fears not just in Katonah, but across Bedford town.

Despite housing several popular public figures and celebrities - including Martha Stewart, Ralph Lauren and Glenn Close among others - the New York City suburb has not faced any huge controversy.   

Monday's incident in the upscale neighbourhood of Bedford was believed to be the first time in several decades that an alarm was raised over violence.

On Tuesday, investigators anonymously revealed some shocking preliminary findings.

A law enforcement officials said that the device was packed in an envelope and was about 8 to 10 inches long. 

The officials also revealed that the package had been photographed by investigators and the images were later reviewed by United States postal inspectors.

The official also noted that the envelope came with markings that were possible aimed at deceiving authorities into believing that the package was sent through the mail.

Later, a report in the New York Times quoted law enforcement officials as revealing that Federal authorities believe that the explosive device was not delivered by the Postal Service but was manually dropped at Soros' property.

In another update, an official pointed out that investigators were now collecting surveillance cameras from the areas surrounding the property, hoping that the person who left the package was captured on tape. 

However, one of the most significant updates of the day came from an unnamed law enforcement official quoted in the Associated Press, who revealed that the device was "not a hoax." 

The official was quoted as saying that investigators found that the device delivered "was not a hoax," and that it "had the components" of an actual bomb, "including explosive powder."

Another official said that the device was constructed from a length of pipe and was about six inches long and was filled with explosive powder.

The senior official pointed out that the pipe bomb was "smaller than what we typically see."

Further, officials also revealed that the device was rigged with a detonator, and it could have maimed or possibly killed someone if it exploded near them.

Meanwhile, a spokeswoman for Soros' Open Society Foundations, Laura Silber issued a statement blaming the country's toxic political environment.

Silber said, "The hateful rhetoric that dominates politics in the U.S. and in so many countries around the world breeds extremism and violence. In this climate of fear, falsehoods and rising authoritarianism, just voicing your views can draw death threats."

She added that Soros is calling on "politicians across the political spectrum to tone down their rhetoric."