(JTA) – President Donald Trump said the Jewish billionaire George Soros was involved in signs featured in protests against the Supreme Court nomination of Brett Kavanaugh.

Trump made the claim Friday on Twitter hours after hundreds of protesters were detained during a sit-in rally in Washington D.C.

“The very rude elevator screamers are paid professionals only looking to make Senators look bad,” Trump wrote. “Don’t fall for it! Also, look at all of the professionally made identical signs. Paid for by Soros and others. These are not signs made in the basement from love! #Troublemakers”

The protest was organized in part by the Women’s March group. Comedian Amy Schumer, who is Jewish, was holding a “We believe Anita Hill” sign, referencing the woman who accused then-Supreme Court nominee Clarence Thomas, now justice, of sexual harassment.

Three women have accused Kavanaugh of sexual assault ahead of the Senate confirmation procedure. Kavanaugh has denied the allegations that date back to the 1980s and were not reported to authorities at the time.

Soros, who is a Hungary-born Holocaust survivor, is a left-leaning donor to the Democrats and other liberal causes in the United States, Europe and Israel. He often features in right-wing conspiracy theories.