As federal and local law enforcement plan to boost their communications with Jewish groups in the United States, Homeland Security Secretary Janet Napolitano on Wednesday told a House panel she is "concerned" over potential threats to the U.S. homeland from Iran or its surrogates and it's "a situation that bears watching."

Napolitano said her department is "conducting a lot of outreach" to Jewish communities across the country to address any concerns after car bombs in two countries overseas targeted Israeli officials and Iranian nationals set off explosions in Thailand.

Jewish groups are also going to receive increased information from some law enforcement, though officials told Fox News they have seen no reason so far to boost security measures or expend additional resources.

In Washington next week, the FBI is set to brief representatives from Jewish institutions around the nation's capital on the latest threat assessment and how to identify and report suspicious activity.

The joint meeting with the FBI's Washington Field Office and the Baltimore Field Office had been planned for weeks, but in light of recent attacks overseas, FBI agents are now expecting the gathering's focus to shift to concern over threats from Hezbollah and Iran, according to one FBI official.

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In particular, the official said, the FBI is planning to brief Jewish representatives on a bulletin they sent out last week, concluding that "recent events" and "recent heightened tensions with Iran" have not "significantly increased the threat" to Jewish personnel in the United States.

On Wednesday, Napolitano told a House panel the U.S. government has still come across "no specific or credible threat against any organization or target in the United States," but her department and the FBI are "constantly monitoring" the activities of Iran's proxy group in Lebanon, Hezbollah.

An official with DHS -- effectively the federal government's counterterrorism liaison with local police departments and private industry -- said there "has not been a change in (security) posture" as a result of events overseas.

The chairman of the House Homeland Security Committee, however, expressed serious concern over what he called a "pending or possible threat" from Iran's proxies, saying "the threat of Hezbollah seems to have emerged (now) more than" ever during the past decade.

Rep. Peter King, R-N.Y., noted last year's foiled plot to allegedly assassinate the Saudi ambassador to the United States on U.S. soil, adding, "Now with the increased tension in the Middle East, I believe that there is a growing, growing threat from Hezbollah."

The Los Angeles Police Department, meanwhile, says it has "increased" its outreach to Jewish institutions and communities in the past couple days, after a bomb plot targeting an Israeli diplomatic car wounded four people in India and a similar plot was foiled Monday in the country of Georgia.

In Bangkok, three Iranian men are now under investigation after a series of blasts Tuesday in a home they were renting.

The commanding officer of the LAPD's Counterterrorism and Special Operations Bureau said his department has not "per se increased security," but it is "concerned" about events overseas and paying an "elevated" amount of attention to activity in their area.

"We have done lots of outreach and asked communities to partner with us in defending the homeland," Deputy Chief Michael Downing said. "There is no credible threat to our region, but that does not mean we shouldn't be prepared for an attack."

Officials in other cities and within federal agencies have echoed Downing's assessment.

"Are our ears a little more perked up? Yes," one source said of the FBI in New York. But in terms of operations, "the situation remains the same" and "nothing's changed," according to the source.

The source said that so far, the FBI is not setting up a command center, nor deploying more agents onto city streets, nor reorganizing squads as a result of events overseas.

Similarly, a New York City Police Department official said his force is "pretty much doing what we've always done" and "not doing anything extra at the moment." But, the official said, the NYPD's Counterterrorism Bureau regularly deploys heavy-weapons "Hercules" teams to locations in the New York City area, and the department could end up sending such teams to local Jewish institutions or facilities.

Jewish institutions around New York City have been asking for more security, the official said. During Wednesday’s House hearing, King noted he too had been contacted by synagogues, but the congressman did not offer any details about the contact.

In Philadelphia, a police official said his department is operating under a "normal course of business," with no additional resources being deployed as a result of events overseas. But, the official said, the department is always concerned about what could happen.

As for whether Israeli facilities are increasing security on their own, an Israeli Embassy spokesman in Washington declined to comment, saying it is standard policy not to discuss security arrangements.

The joint FBI-DHS bulletin, dated Feb. 8 and obtained exclusively by Fox News, said threats against Israeli or Jewish targets in Asia and Europe, attacks on nuclear scientists in Iran, global economic sanctions against Iran, and reports of Israel's "possible intent to attack Iran's nuclear facilities" have "contributed to the perception of an increased threat to the Jewish community worldwide from Iran or its surrogates."

The bulletin acknowledged that Jewish personnel inside the United States "have been a focus of violent extremists in the past" and they "will likely remain a target" in the future.

"Economic sanctions and the threat of military action against the Iranian nuclear program suggest tensions with Iran are likely to continue, and we remain concerned Iran would consider attacks in the United States, given last year's foiled plot to allegedly assassinate the Saudi ambassador," reads the bulletin, which suggested a series of "protective measures" for local law enforcement to take.