US security officials are on alert for possible retaliatory attacks against Democrats following the attempted assassination of former President Donald Trump, according to a new intelligence report obtained by CNN.

The threat assessment — prepared jointly by the FBI, Department of Homeland Security, and other agencies, including local police in Illinois — outlines various potential security concerns surrounding the upcoming Democratic National Convention in Chicago.

“The FBI and DHS remain concerned about the potential for follow-on or retaliatory acts of violence following the 13 July 2024 assassination attempt on (Trump) particularly given that individuals in some online communities have threatened, encouraged, or referenced acts of violence in response to the attempted assassination,” the assessment says, noting agencies have not identified any specific and credible threats.

While the motive of the gunman who fired on Trump remains a mystery to investigators, the bulletin says “politically and socially divisive topics have prompted violence in the past,” and adds that some extremists “will view political and social tensions as an opportunity to use or promote violence to further their ideological goals.”

The intelligence assessment is common for major gatherings deemed national security special events by the DHS secretary, and it includes many of the security concerns outlined in a joint report federal law enforcement issued last month ahead of the Republican National Convention in Milwaukee.

CNN has reached out to DHS and the FBI for comment on the threat assessment.

The Democratic convention kicks off August 19 and is expected to draw over 50,000 visitors to downtown Chicago, including numerous high-profile individuals such as President Joe Biden, Vice President Kamala Harris and a host of elected leaders nationwide.

It starts in the wake of numerous recent troubling security incidents involving mass gatherings of people worldwide, including the attack on Trump at a campaign rally in Butler, Pennsylvania, that killed an audience member and wounded others, including the former president. That incident prompted bipartisan criticism of the Secret Service and the failure to properly secure a building near the large gathering used by the gunman to fire down into the crowd.

On Wednesday, authorities in Austria announced the arrest of three suspected ISIS sympathizers who were allegedly planning a suicide attack on a Taylor Swift concert. Security officials believe the individuals were radicalized online, and concerns over event safety prompted the cancellation of three Swift concerts.

In their intelligence assessment for the Democratic National Convention, the FBI and DHS say the most significant terrorism threat facing the event stems from extremists “including lone offenders, who engage in violence to advance a broad range of anti-government, political, racial, ethnic, religious, societal, or personal ideological beliefs and grievances.” The agencies note that groups like al Qaeda and ISIS “have encouraged attacks against the West and leveraged social media to amplify their messaging to inspire attacks in the Homeland.”

“I think everyone has a sense that the threats are real. This is not an academic exercise that we’re running through. We are planning for real-world possibilities,” Jeff Burnside, the Secret Service coordinator for the Democratic convention, said previously about security preparations.

Middle East tensions following last year’s Hamas terrorist attack on Israel could also fuel public safety concerns at the upcoming convention in Chicago, the assessment states.

Since the October 7 attack, law enforcement has observed an increase in threats to Jewish, Muslim, and Arab communities in the US, “including reports of physical assaults, bomb threats, and online calls for mass casualty attacks,” the threat assessment says. “As violent rhetoric and misinformation associated with the conflict are shared online, we continue to be concerned about the potential for reportable targeted violence motivated by grievances exacerbated by the conflict.”

As CNN has reported, recent demonstrations across the country against the Biden administration’s support for Israel’s war in Gaza have raised the specter of a replay of the 1968 Democratic convention, which saw violent clashes between Chicago police and anti-Vietnam War protesters.

With the start of the convention just over a week away, law enforcement agencies in Chicago have been holding drills on a wide range of potential scenarios — including violent protests, extracting individuals from hostile crowds, medical emergencies and more.

CNN’s Sean Lyngaas and John Miller contributed to this report.