Authorities in South Florida arrested a man after police say he slapped and punched a U.S. Postal Service worker in the face and ripped off her hijab late last month. A woman intentionally rammed her car into what she thought was a Jewish school last week in Indiana. Meanwhile, civil rights groups say threats against Jewish and Muslim people, including local faith leaders and federal officials, are being reported in staggering numbers across the country.

Such incidents appearing to target Jewish and Muslim people have surged across the nation since the start of the Israel-Hamas war just over a month ago, putting all levels of law enforcement agencies on high alert and instilling fear into the lives of those being targeted and attacked.

Several colleges from the San Francisco Bay Area to Upstate New York have seen increasing antisemitic and Islamophobic incidents that have prompted politicians and civil rights organizations to speak out. And local officials throughout the country have bolstered surveillance and security measures at mosques and synagogues.

After Paul Kessler, a 69-year-old Jewish man, died on Monday from a head injury he received in an altercation at dueling pro-Palestinian and pro-Israel demonstrations in southern California, the local sheriff announced increased deputy presence around Muslim and Jewish houses of worship.

"We understand that the war in Israel and Gaza has led to an increase in hateful and threatening rhetoric, and we want to assure the Muslim and Jewish communities that we stand with them both during this difficult time," said Ventura County Sheriff Jim Fryhoff on Tuesday. The case is being investigated as a homicide, and deputies have "not ruled out the possibility of a hate crime," Fryhoff said.

In late October, top FBI officials held a call with more than 2,400 heads of local police departments, including those on college campuses, urging them to share information they may gather on potential threats, The Washington Post reported.

At a U.S. Senate Homeland Security Committee hearing last week, FBI Director Christopher Wray said the agency's "most immediate concern" is violent extremists – individuals or small groups – who may "draw inspiration from the events in the Middle East to carry out attacks against Americans going about their daily lives."

"The greatest terrorism threat to our homeland is posed by lone actors or small cells of individuals who typically radicalize to violence online, and who primarily use easily accessible weapons to attack soft targets," he said.

Surge of violence against Jewish and Muslim people

At the Senate hearing last week, Wray pointed to two incidents that have the FBI, state and local law enforcement agencies on high alert.

Last week, authorities arrested Sohaib Abuayyash, a 20-year-old a Jordanian citizen living in Houston, who had studied how to build bombs and "posted online about his support for killing Jews," Wray said.

Wray also mentioned the arrest of 71-year-old Joseph Czuba, a man charged with the fatal stabbing of 6-year-old Wadea Al-Fayoume and wounding his mother, Haanan Shahin, at their Illinois home. Czuba was the family's landlord for two years and had no reported problems with them until the brutal attack in October.

According to text messages between Shahin and the boy's father, Czuba yelled "You Muslims must die" during the attack. Czuba's wife, Mary, said her husband listened to a "conservative talk radio on a regular basis" and had been "heavily" interested in recent events in Israel, according to court documents.

More recently, a U.S. Postal Service worker in full uniform was walking up to a residence in Fort Lauderdale, Florida, to deliver mail when Kenneth Pinkney, 47, rode past her on a bike and told her to go back to her country, an arrest affidavit said. Pinkney then walked up to the woman, who was not identified in court records, ripped of her hijab, and punched and slapped her in the face. Pinkney was arrested Oct. 24.

On Friday, Indianapolis police say Ruba Almaghtheh, 34, drove her Chevy Impala into the Israelite School of Universal and Practical Knowledge. Investigators said in court records that she referred to the building as an "Israel school." The building, however, is associated with Radical Hebrew Israelites, a group the Southern Poverty Law Center has designated as an anti-Israel and antisemitic extremist organization. A police report indicated investigators believe the crash was spurred by hatred. Local officials have notified the FBI.

On Saturday, authorities in Arizona arrested 50-year-old Jeffrey Mindock after investigators say he sent an email to the rabbi of a synagogue threatening to “execute” him and other Jewish people.

Meanwhile, in Minnesota, police are investigating the attack of a Muslim woman at a Minneapolis gas station where the suspected assailant reportedly pulled out a small knife and assaulted the woman. Minnesota's CAIR, or Council on American–Islamic Relations, on Tuesday called for a "bias probe" into the incident.

Threats target US civilians and members of Congress

CAIR-Chicago wrote last month that the nonprofit civil rights organization has received dozens of threatening calls and emails each day since the start of the war. The organization has also recorded an increase of reported hate crimes, including visibly Muslim women who have been taunted and targeted with slurs in public places.

Rep. Ilhan Omar, D-Minn., one of the few Muslim members of Congress, told NBC News she fears her life may be in danger, citing repeated death threats she has received since early October. The outlet reported one message in which the congresswoman was called “terrorist Muslim." Another message claimed there was a "vigilante group" spying on Omar and her children.

The Anti-Defamation League in late October released preliminary data indicating that reported incidents of antisemitism, including harassment, vandalism and assault against Jews from Oct. 7 to Oct. 23 increased by 388% when compared with the year before. The ADL recorded 312 antisemitic incidents over the roughly two-week period this year. Of those, 190 were "directly linked to the war in Israel and Gaza."

Late last month, federal authorities arrested John Anthony Miller, 43, after he threatened Sen. Jacky Rosen, D-Nev., with repeated antisemitic phone messages, including one that said “we’re gonna finish what Hitler started,” according to court records. An Oct. 19 message accused Israelis of killing Christians in the West Bank and said Rosen would burn in hell for her crimes, court records said.

Wray, the FBI director, said in his opening remarks to the Senate committee last week that the Israel-Hamas war "has raised the threat of an attack against Americans in the United States to a whole other level."

“This is not a time for panic, but it is a time for vigilance,” Wray said. “You often hear the expression 'If you see something, say something.' That’s never been more true than now, and that’s probably partly why the American people are reporting more tips and leads to us, and we’re pursuing those threats and leads as vigorously and responsibly as we can."

Contributing: Minnah Arshad, Will Carless and Bart Jansen, USA TODAY