Police in New York, Los Angeles, and other US cities increased patrols, authorities put up fencing around the US Capitol and some schools closed Friday amid fears of violence inspired by the Israel-Hamas war. But law enforcement officials stressed there were no credible threats in the US.

A former Hamas leader's call for a "day of rage" put American Jewish communities on edge, and sparked heightened security around houses of worship, schools and cultural institutions. The jitters were a sign of just how much the war between Israel and Hamas is reverberating around the world, striking fear in communities even in the absence of a credible threat.

Law enforcement officials said they were on high alert for violence driven by antisemitic or Islamophobic sentiments in the wake of the Hamas attack on Israel. Jewish and Muslim groups have reported an increase of hateful and threatening rhetoric on social media.

"We cannot and do not discount the possibility that Hamas or and other foreign terrorist organizations could exploit the conflict to call on their supporters to conduct attacks here on our own soil," FBI Director Christopher Wray told Jewish community leaders at a security briefing on Thursday.

Ashley Reyes, 40, who is Jewish and lives in Montclair, New Jersey, said the escalating conflict has made her feel less safe and has sparked worries for her 10-year-old son.

"This is the first time in my life that I have actively thought of saying to my son, If someone asks you if you're Jewish or if your mom's Jewish, you say no," Reyes said.

At the Palestinian American Community Center in Clifton, New Jersey, Executive Director Rania Mustafa said there has been an increase in harassing phone calls, emails and messages on social media. Mustafa said the group has closed its doors and is only letting in people they know or who identify themselves.

"It's been a very stressful week in all regards, from one end trying to convince the world that we're human and that our lives are as sacred as anyone else's lives and on the other end, trying to protect our own from being targeted. And protecting freedom of speech, of expressing opinions and solidarity with the Palestinian people," she said.

New York City Mayor Eric Adams told reporters Thursday that police would do extra patrols in some city neighborhoods and send additional resources to schools and houses of worship. There has been a large police presence at protests, rallies and vigils in the city over the past week. Some synagogues have also said they would have private security guards.

Adams and New York Gov. Kathy Hochul stressed that law enforcement wasn't aware of any credible threats against the state or the city.

"We want to reiterate to New Yorkers: There's no reason to feel afraid. No one should feel they have to alter their normal lives or their routines; and indeed when we change our behavior without a serious credible threat, then we're letting the terrorists win," Hochul said.

"I want all New Yorkers to feel confident going to a synagogue, going to school, walking in the streets of New York and throughout our state."

Meanwhile, a New York City councilmember was arrested Friday for bringing a handgun to a student demonstration supporting Palestinians.

Inna Vernikov, a Republican who is Jewish, has been among the most outspoken opponents of Palestinian activists, describing the protesters as "terrorists" while accusing them of making Jewish students feel unsafe. She was seen in photos and videos with the butt of a pistol jutting from her waistband. Vernikov did not immediately respond to an emailed request for comment and messages left at her offices were not returned.

New York City's public university system has seen a wave of duelling protests in recent days following the Hamas attack on Israel and escalating war in Gaza.

Columbia University halted public access to its Manhattan campus Thursday in advance of a planned demonstration by pro-Palestinian activists and a rival pro-Israel group, saying only students, faculty and credentialed journalists would be allowed in. The demonstrations wound up being peaceful.

In Washington, crews were seen putting metal barriers outside the Capitol Thursday evening. A Capitol police spokesperson said in an email they were "not taking any chances" even though there are no specific threats.

Las Vegas' Innovations International Charter School, which has a campus located in a former Jewish temple, said Friday they were cancelling classes out of an "abundance of caution." Charles E. Smith Jewish Day School in Rockville, Maryland, also closed its campuses, telling parents in an email that there was no specific threat to the school, but it, too, was acting out of "an abundance of caution."

Los Angeles, police said they were reaching out to Jewish and Muslim communities and providing extra patrols. Police in Westchester County, New York, also said they were increasing patrols around schools and Jewish houses of worship on Friday. In Boston, police since the beginning of the conflict have increased their uniformed presence around religious and cultural institutions, a spokesperson said Friday.

The Secure Community Network, which advises US Jewish institutions on security, has encouraged Jewish communities to be vigilant and bolster their security efforts. But the group has advised institutions there is no need to close their doors, absent specific information otherwise from law enforcement.

Michael Masters, the group's CEO, warned against letting "fear or clickbait threats cause chaos" in Jewish communities because he said that is part of the objective of those spreading hateful rhetoric online.

"We saw some of the worst of humanity on Saturday, but we also saw some of the best," he said of the horrific Hamas attack. "People rushing with literally nothing at their disposal to the lives of family, friends and people they don't know."

"I think we owe it to them that we are not going to give in easily and that we are not going to bow down ... because others wish for us to go away."