CNN
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In light of Iran’s recent attack on Israel and the start of the Jewish holidays on Wednesday, police departments across the U.S. are increasing patrols in Jewish communities and places of worship.

Officials told CNN that the increased police presence in key locations is out of caution and deterrence and is not based on specific threats. Despite the lack of known credible threats, law enforcement has described the possibility of violence from so-called “lone wolf” attackers as one of their biggest concerns in what they have described as a heightened threat environment.

The increased patrols come as Rosh Hashanah – the first high holiday and Jewish New Year – is scheduled to begin at sunset on Wednesday and end at dusk on Friday. Next week, Yom Kippur, the holiest day in the Jewish calendar, will be celebrated from Friday at sunset until nightfall on Saturday.

The NYPD adopted an increased patrol posture on Monday, a law enforcement source told CNN, which is expected to remain in place for the next two weeks.

The NYPD will also work with state police on explosives detection missions on bridges and tunnels, and helicopter units will be used for radiation detection, the source said.

Los Angeles police leaders recently attended a safety town hall with Jewish community leaders in Southern California to discuss increasing patrols during the religious holidays. Due to unrest in the Middle East, the LAPD has regularly increased its presence at Jewish and Muslim houses of worship.

Last week at City Hall, the LAPD said its patrols would include larger numbers of field officers, command post vehicles and mounted units. The meeting was intended to reassure members of the Jewish community, many of whom have expressed concerns about safety after an anti-Semitic attack in the city last year in which two men were shot as they left a Jewish synagogue by a man on Monday was sentenced to 35 years in federal prison.

Chicago police said the department plans to “pay particular attention to places of worship” and will monitor all activities. “While there is no actionable intelligence at this time, we will have an increased police presence to ensure the city’s faith communities are not only safe, but feel safe,” the department said in a statement.

When asked about the attack on Israel on Tuesday, a spokesman for the Miami Beach Police Department said it had “increased our uniformed presence throughout the city to ensure public safety.”

The Philadelphia Police Department told CNN it is closely monitoring the situation in Israel “and assessing any possible impact on our local community.” Out of an abundance of caution, we have taken proactive measures, including increased patrols around local Jewish and Islamic houses of worship and community centers, to ensure the safety of all community members.”

In addition to law enforcement, national Jewish security organizations have worked to identify potential threats to houses of worship in the United States.

“What we have previously told Jewish institutions is that there is currently no known credible threat to the Jewish community in the United States,” said Oren Segal, vice president of the Center on Extremism at the Anti-Defamation League, adding the organization recommends that places of worship remain open during the high holidays.

“However, given the heightened tensions and increased risk to the community at this time, we recommend that institutions review and implement a range of security precautions and procedures,” Segal said.

CNN’s Whitney Wild, Ryan Young, Mark Morales and Brynn Gingras contributed to this report.