Highlights: The F.B.I. director warned Tuesday that the Israel-Hamas war had raised the potential for an attack against Americans to a new level and escalated threats against Jews and Muslims in the United States.

Christopher A. Wray, the F.B.I. director, said foreign terrorist organizations had called for violence against Jews after the Oct. 7 terrorist attacks by Hamas assailants prompted Israel to besiege and bombard the Gaza Strip, where Hamas is in control.

The number of antisemitic acts in the United States had been on the rise even before the Israel-Hamas war, led in part by white supremacist propaganda and new nationalist groups across the country. But since the attack by Hamas on Oct. 7, the drumbeat of antisemitic threats and acts has drastically increased.

Mr. Wray cited several foreign terrorist groups who have issued calls to attack Americans, and Jews in particular, in the wake of the attacks by Hamas.

The Islamic State, also known as ISIS, has called for attacks on Jewish communities in the United States and Europe, and Al Qaeda issued a specific call to attack the United States, Mr. Wray said.

Alejandro N. Mayorkas, the secretary of homeland security, said that since Oct. 7, federal officials have responded to an increase in threats against “Jewish, Muslim and Arab American communities and institutions across our country.”

Jews represent less than 3 percent of the American population, but even before Oct. 7 they were the target of about 60 percent of the religious-based hate crimes, Mr. Wray said, citing statistics from 2022.

Between Oct. 7 and Oct. 23, there were 312 antisemitic acts in the United States, 190 of which were directly linked to the war, according to the Anti-Defamation League. Those include an incident on Oct. 15 at Grand Central Terminal in New York when someone reportedly punched a Jewish woman in the face because she was Jewish.