Law enforcement officials responded to an incident at the home of liberal billionaire George Soros on Monday evening, an officer with the Bedford, New York, police department told HuffPost.

A Soros employee opened a package containing an explosive device and called police Monday afternoon, prompting bomb squad technicians to come detonate it, The New York Times reported.

A law enforcement source told The Associated Press that the device contained explosive powder and was “not a hoax device.”

Soros has been a frequent target of conspiracy theories and fear-mongering by hypernationalist conservatives in the U.S. and Europe, who often rely on anti-Semitic tropes when they characterize him as a shadowy figure encouraging mass migration and torpedoing traditional Christian culture. President Donald Trump has personally attacked him as well.

A spokesman for Soros declined to comment on the record about the role that such rhetoric might have played in inspiring an attempted attack on the billionaire. The Anti-Defamation League did not immediately respond to a request for comment.

Soros ― who survived the Nazi occupation of Hungary, fled with the rise of communism and then made his money on Wall Street ― has focused on promoting democratic priorities like freedom of the press, less discrimination in the justice system and a protected role for nongovernmental institutions. He announced last year that he would give his remaining wealth, around $18 billion, to his primary vehicle for philanthropy, the Open Society Foundations.

While Soros foes cast him as an unabashed leftist, his defenders note that his focus has been on the rule of law. Conservatives, including his chief international critic Hungarian Prime Minister Viktor Orban, have benefited from his largesse.

Republicans have increasingly vilified Soros since Trump suggested he was behind popular protests against Supreme Court Justice Brett Kavanaugh’s confirmation. Groups that track hate speech warned that such rhetoric could boost extremism, but official GOP organs doubled down.

“When Trump and his Republican enablers scoff that today’s protesters are Soros-paid puppets, they are doing far more than scoring cheap political points against their adversaries,” historian Neil J. Young wrote for HuffPost last week. “Dangerously, they are sowing the kind of division and distrust among Americans that threatens our entire democracy.”

The FBI is investigating the incident, CNN reported Monday night.

This article has been updated with the AP report about the device containing explosive powder.