During Thursday’s federally-contracted fast food worker protest on the National Mall, a freelance photojournalist was grabbed by a group of security guards inside the Smithsonian’s Air and Space Museum.

Kristoffer Tripplaar, who was shooting as a contract photographer for Sipa USA, told DCist he entered the museum to photograph a group of protesters, including one man who was yelling. There were other photographers and videographers present, including one from the Associated Press who would capture Tripplaar’s incident with the guards.

“We were around the [yelling] guy taking pictures … and one of the security guys grabbed one of the guys who was shooting video,” he explained, “and started pushing him out. And [the guard] was pushing [the man with the camera] out right towards me, and I leaned in to take the blow [from his body, not a punch]. He was coming right at me when I saw him. I leaned to take the blow because I thought he was gonna [run into] me, so I could protect my cameras. And then the security guy ended up running into me. And then another security guy ran over and started yelling, ‘He [as in Tripplarr] hit you! He hit you!’ And then a couple seconds later is what happened in those photos.”

Tripplaar said the guards slammed him into the ground. Another security guard who identified himself as a supervisor came over and told the guards to let go of him. “He even offered to help me up,” Tripplaar said, “and I just refused. And I said, ‘You’ve got to get these guys away from me before I’m gonna get up.’ Because I was worried that they were gonna grab me again.” The supervisor did that, and Tripplaar went back to taking photos. He walked away without any damage to his cameras and a few bruises.

After the melee, Tripplaar said he contacted the Smithsonian press office and asked how he could proceed with filing a complaint: “I’ve been doing this for almost ten years. I cover everything from the White House to the Capitol. I’ve done countless protests, some of them got pretty heated and a little pushy. And I’ve never, ever, ever had something like this happen to me. Ever.”

A person from the press office replied to Tripplaar, he said, with an email address to send a complaint to, which he plans to do.

A Smithsonian spokesperson told DCist the head of the Office of Protection Services is looking into the allegations and has the photos. No further information was available at this time.

“I’m certainly embarrassed that the most interesting picture to come out of that entire protest is me getting my ass kicked,” Tripplaar said with a laugh. “When I show up to something like that, the game plan is not really to show up on the AP wire being beat up.”

But even though he’s uncomfortable with the attention, he says “people should know that it happened.”

Tripplaar doesn’t have an exact idea of what he wants to come out this incident, but said “it’d be nice to get some sort of apology or an acknowledgment from the Smithsonian that, ‘Hey, this is not how we want to handle things.'”