WASHINGTON (AP) Donald Trumps campaign was warned about not taking photographs before an altercation at Arlington National Cemetery during a wreath-laying ceremony earlier this week to honor service members killed in the Afghanistan War withdrawal, a defense official told The Associated Press on Wednesday.

The official spoke on condition of anonymity to discuss a sensitive matter concerning Mondays events. It came a day after NPR reported, citing a source with knowledge of the incident, that two Trump campaign staff members verbally abused and pushed aside a cemetery official who tried to stop them from filming and photographing in Section 60, the burial site for military personnel killed while fighting in Afghanistan and Iraq.

The defense official told the AP that the Trump campaign was warned about not taking photographs in Section 60 before their arrival and the altercation. Trump was at Arlington on Monday at the invitation of some of the families of the 13 service members who were killed in the Kabul airport bombing exactly three years prior.

Arlington National Cemetery is the resting place for more than 400,000 service members, veterans and their families. Cemetery officials said in a statement that an incident had occurred and a report had been filed, but it did not address details of what had happened. They declined to share the report.

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 candidates campaign, the cemetery officials statement said. Arlington National Cemetery reinforced and widely shared this law and its prohibitions with all participants. We can confirm there was an incident, and a report was filed.

Trumps spokesperson Steven Cheung said the Republican presidential candidates team was granted access to have a photographer. He contested the allegation that a campaign staffer pushed a cemetery official.

The fact is that a private photographer was permitted on the premises and for whatever reason, an unnamed individual, clearly suffering from a mental health episode, decided to physically block members of President Trumps team during a very solemn ceremony, he said.