A volunteer member of the advance team for President Trump blocked a photojournalist's camera as he tried to take a photo of a protester during a campaign rally in Indiana Thursday night. The volunteer has since been taken off the road, the Trump campaign told the White House Correspondents Association.

A photo taken by Associated Press photographer Evan Vucci in Evansville shows the volunteer stretching out his hand over the lens of a news photographer's camera after a protester disrupted Mr. Trump's campaign event.

Olivier Knox, the WHCA president, says Mr. Trump's campaign told him the actions were those of an "inexperienced volunteer, who understands that he acted in error." Knox says the campaign "promises that this will not happen again."

A volunteer member of the advance team for President Trump blocks a camera as a photojournalist attempts to take a photo of a protester during a campaign rally at the Ford Center, Thursday, Aug. 30, 2018, in Evansville, Ind. Evan Vucci / AP

The president was in town to stump for Republican Senate candidate Mike Braun, who is looking to unseat Democratic Sen. Joe Donnelly in what is viewed as one of the nation's most competitive Senate races.

Get Breaking News Delivered to Your Inbox

In the same rally, Mr. Trump railed against social media companies for, as he said, censoring free speech. The president has recently criticized websites such as Google, Facebook and Twitter for supposedly silencing conservative voices. Mr. Trump became vocal about this issue after several sites removed pages by Alex Jones, a controversial right-wing conspiracy theorist. Mr. Trump also said earlier this week that Google was filtering search results about him to only show negative news.

"There's a thing called free speech rights," Mr. Trump said at the rally. "I've made it clear that we as a country cannot tolerate political censorship, blacklisting, and rigged search results."

"We will not let large corporations silence conservative voices," the president said.