Arlington National Cemetery officials on Tuesday acknowledged an unspecified “incident” during Donald Trump’s visit on Monday on the three-year anniversary of the Afghanistan withdrawal, as dueling allegations of misbehavior overshadowed an event to honor American war dead.

An NPR report on Tuesday cited an unidentified source with knowledge of the incident who said Trump campaign staff pushed and verbally attacked a cemetery official who tried to stop them from taking photos and video in an area of the cemetery called Section 60 where many U.S. service members who died in recent conflicts are buried. The cemetery said in a statement that federal law bars photography for political campaign purposes at the site.

But Trump campaign communications director Steven Cheung said that “there was no physical altercation as described,” that the campaign was given permission to bring a photographer, and that they are “prepared to release footage” to defend against “defamatory claims.”

Cheung also claimed, without providing evidence or details, that “an unnamed individual, clearly suffering from a mental health episode, decided to physically block members of President Trump’s team during a very solemn ceremony.”

Responding to an inquiry about an alleged altercation during Trump’s visit, Arlington National Cemetery issued a statement that read: “We can confirm there was an incident, and a report was filed.” The organization did not share more details. It was not immediately clear to whom the report was filed, but the incident occurred on U.S. Army property. Army headquarters and the service’s criminal investigation division did not immediately respond to requests Tuesday night for clarification.

Visitors have long taken graveside photographs in Arlington National Cemetery, including in Section 60. But in a statement released on Tuesday, defense officials drew a distinction between Trump’s actions and those of typical visitors.

“Federal law prohibits political campaign or election-related activities within Army National Military Cemeteries, to include photographers, content creators or any other persons attending for purposes, or in direct support of a partisan political candidate’s campaign,” the cemetery’s statement said. “Arlington National Cemetery reinforced and widely shared this law and its prohibitions with all participants.”

The Trump campaign did not immediately share the footage they claimed to have.

They shared a statement from Cheryl Juels, whose niece Nicole Gee died in the Afghanistan exit and who joined Trump at the cemetery on Monday. Juels said she and her family “absolutely welcomed and appreciated having video and photography there with us during the time we spent with President Trump.” She praised Trump for visiting Section 60 to lay flowers at gravesites, talk with family members and discuss Gee’s life.

Trump visited the cemetery on Monday on the third anniversary of an Aug. 26, 2021, suicide bombing that unfolded outside the Kabul airport as the U.S. pulled out of Afghanistan, killing 13 American service members and scores more Afghans.

As president, Trump struck a deal with the Taliban to exchange prisoners and set a timetable to withdraw American forces from Afghanistan. But he criticized the ultimate exit during the Biden presidency, saying the execution was botched.

The GOP presidential nominee joined a wreath-laying ceremony at the Tomb of the Unknowns and spoke with relatives of those slain in the Kabul bombing, as his campaign attacked the Biden administration’s handling of the Afghanistan exit.

“This month marks the three-year anniversary of the most embarrassing moment in the history of our country,” Trump said in a video posted to his Truth Social account that day.

The allegations published by NPR come as Trump pitches himself as a champion of the military but also faces scrutiny of his comments on veterans. Trump’s former chief of staff, John Kelly, has publicly accused him of referring to American War casualties as “suckers,” an allegation Trump denies.

Trump also drew fire earlier this month for saying that an award recognizing civilian contributions to society is “much better” than one bestowed on members of the military because many of those who receive that award are wounded or killed in combat.

Top campaign adviser Chris LaCivita said in a statement Tuesday that Trump went to the Arlington Cemetery at the invitation of Gold Star families who lost loved ones in the U.S. withdrawal from Afghanistan and added: “For a despicable individual to physically prevent President Trump’s team from accompanying him to this solemn event is a disgrace and does not deserve to represent the hollowed [sic] grounds of Arlington National Cemetery.”

LaCivita, who was wounded in combat as Marine, has led GOP efforts to criticize Democratic vice-presidential nominee Gov. Tim Walz’s descriptions of his military record and previously helmed the Republican campaign to attack John F. Kerry’s military service in the 2004 election.

Arlington National Cemetery is considered hallowed ground in the U.S. military, and is managed by the Army. Section 60, where Trump visited Monday, is the final resting place for many U.S. service members who were killed in recent conflicts, including some of the U.S. service members who died in the Afghanistan suicide bombing.

Hau Chu contributed to this report.