After the International Civil Rights Center and Museum in Greensboro, North Carolina denied the Donald Trump campaign’s request told hold a lengthy private tour for the candidate, the museum has received several threats, the News and Observer reported.

“The callers were threatening to come over and burn down the building and to shoot up the building,” John Swaine, the museum’s CEO, told the News and Observer. “They’ve lessened in frequency this week, but they’re still coming in.”

He said that the museum has received the threatening messages on social media and phone calls with racial slurs since the news broke in late September that the museum had denied Trump’s request for a private visit.

Swaine said that he denied the Trump campaign’s request for a tour on Sept. 20 because the campaign asked for the museum to be closed for five hours and for Trump to be videotaped walking through the exhibits.

“We made it known to Mr. Trump’s campaign that we were not going to grant a request of suspending our operations so he could somehow try to legitimize his ideological positions,” he told the News and Observer. “The landmark is very important – it’s not just a political backdrop.”

He said that the museum, which is located in the former F.W. Woolworth building, where the historic sit-in protest took place in the 1960s, does allow high-profile officials to take private tours of the museum. But he said that museum employees who spoke to the Trump campaign said that they did not request a tour, and he said it seemed like the Trump campaign was looking for a photo-op, according to the News and Observer.

Trump’s campaign spokesman in North Carolina, Kirk Bell, told the News and Observer that the campaign “is not commenting on this matter.”