An explosive device was found on Monday near the Westchester County home of George Soros, the billionaire philanthropist who is a favorite target of right-wing groups, according to a law enforcement official.
The device did not explode on its own, and bomb squad technicians “proactively detonated” it, the official said.
The Bedford Police Department and the Westchester County Department of Public Safety said Monday night that they were investigating at that location. The police declined to answer questions but said that a hazardous device unit had been requested.
The F.B.I. and the Bureau of Alcohol, Tobacco, Firearms and Explosives did not respond to requests for comment.
It is unclear if Mr. Soros was home at the time. His foundation did not immediately respond to a request for comment.
Mr. Soros, who was born in Hungary, made his fortune running a hedge fund and is now a full-time philanthropist and political activist. He donates frequently to Democratic candidates and progressive causes and has given at least $18 billion to his Open Society Foundations to promote democracy and human rights around the world.
His activism has made him a villain to conservative groups and the target of anti-Semitic smears. Roseanne Barr called him a Nazi in an infamous tweetstorm, and Representative Matt Gaetz, Republican of Florida, falsely speculated that Mr. Soros had funded a caravan of migrants moving north toward Mexico.