FBI posts warning about Fourth of July 'attacks' ahead of celebrations - and urges people to watch out for specific kind of security threat

Fourth of July revelers should be on high alert for possible lone wolf 'attacks' as they celebrate the holiday, the FBI and Homeland Security warned. 

The security agencies said solo attackers and small extremist groups pose the biggest threat, cautioning that large crowds are often seen as 'attractive targets.' 

Experts warn that high tensions across the nation due to the presidential election and the ongoing Israel-Hamas war are heightening the risks, and lone-wolf attacks are alarmingly hard to prepare against. 

'The police are being told by the FBI and Department of Homeland Security to be on watch for these types of things that are notoriously difficult to guard against,' security correspondent Aaron Katersky told ABC News

'The political environment of the country certainly doesn't help.' 

Security agencies are warning Fourth of July revelers to remain 'vigilant' as they celebrate the national holiday

Security agencies are warning Fourth of July revelers to remain 'vigilant' as they celebrate the national holiday 

Law enforcement cautioned that lone wolf attacks are the biggest threat, and large crowds are often seen as 'attractive targets'

Law enforcement cautioned that lone wolf attacks are the biggest threat, and large crowds are often seen as 'attractive targets' 

The federal warning, which was also issued by the National Counterterrorism Center, urged police departments across the nation to be vigilant amid the celebrations. 

Although such bulletins are not uncommon before a national holiday, this July Fourth warning notably cites 'domestic' attacks that could be triggered by issues also including abortion and racism. 

Such terrorists would 'likely would use simplistic tactics and relatively easily obtainable weapons such as firearms, knives and vehicles.' 

The bulletin adds that while the security agencies are not currently aware of any active plots to target the celebrations, attacks 'can occur with little to no warning.' 

As huge crowds take to the streets in major cities across the nation, police departments will be stretched thin and resources will be strained. 

The FBI warning notes that this can severely hamper the ability for cops to stop an attack before it happens, as they can 'occur with little to no warning because of the frequently lower levels of security around civilian targets.' 

Police are also faced with 'challenges in securing large crowds', with past Fourth of July attacks evidencing why this poses an increased threat. 

The most recent tragedy came in 2022 at Chicago's Highland Park July Fourth parade, where gunman Robert Crimo, 22, opened fire on huge crowds and killed seven. 

At least 24 others were hospitalized in the shooting, with Crimo firing rounds down onto the throng of people from a perch. 

A police officer bows his head in grief next to abandoned strollers and chairs after a shooting that killed six people in Highland Park, Illinois, in 2022

A police officer bows his head in grief next to abandoned strollers and chairs after a shooting that killed six people in Highland Park, Illinois, in 2022 

Law enforcement officers look over a park near the scene of a mass shooting at a 4th of July celebration and parade in Highland Park, Illinois, in 2022

Law enforcement officers look over a park near the scene of a mass shooting at a 4th of July celebration and parade in Highland Park, Illinois, in 2022

Katersky advised anyone planning on joining large events to avoid panic, but to also 'keep your head on a swivel and if you see something untoward, mention it.' 

Chicago police affairs consultant Bill Kushner told ABC7 Chicago that in his opinion, the greatest threat could be posed by those being radicalized by the Israel-Hamas war. 

'The Israeli-Palestinian issue, where we've seen discord on college campuses, we've seen a lot of protesting and it seems to be growing violence,' he said. 

'I would be more concerned about that aspect of it than anything else.' 

Kushner advised that to mitigate the danger of a lone wolf attack, attendees should scope out possible exit routes at parades and gatherings. 

In a statement to ABC7 Chicago, a spokesperson for the city's FBI bureau said that the warnings come as the bureau 'regularly shares information' with law enforcement, but 'encourages members of the public to be vigilant and report anything they consider suspicious to' police. 

Millions of Americans are set to take to the streets across the nation, stretching police resources thin

Millions of Americans are set to take to the streets across the nation, stretching police resources thin 

Experts advised those planning on joining large events to avoid panic, but to also 'keep your head on a swivel and if you see something untoward, mention it'

Experts advised those planning on joining large events to avoid panic, but to also 'keep your head on a swivel and if you see something untoward, mention it' 

Much of the focus appears to have fallen on domestic terrorism, with the FBI saying it is tracking around 850 suspected 'domestic' terrorists, following a significant increase in domestic terrorist cases involving white supremacists.   

'In fact, there have been more arrests and deaths in the United States caused by domestic terrorists than international terrorists in recent years,' Assistant Director Michael McGarrity, the head of the FBI's counterterrorism division, told a Congressional hearing recently. 

However, the FBI bulletin also warned that ISIS has also recently called for supporters to target the United States. 

The bureau says it is monitoring around 1,000 suspected 'homegrown' terrorists currently residing in the United States, inspired by terrorist organizations including ISIS and al Qaeda. 

In a statement to ABC News following the release of the bulletin, an FBI spokesperson urged members of the public to 'maintain awareness.' 

'The FBI regularly assesses intelligence regarding possible threats to the U.S. and will continue to work closely with our federal, state, and local law enforcement partners should there be any potential threat to public safety,' the spokesperson said. 

'We ask members of the public to maintain awareness of their surroundings and to report any suspicious activity to law enforcement immediately.'