Walmart has pulled a t-shirt advocating violence against journalists from its online store after a professional organisation warned of the threat.

The t-shirt, which Walmart offered via a third party vendor called teespring.com, featured the phrase “Rope. Tree. Journalist. SOME ASSEMBLY REQUIRED”. In a letter to Walmart executives, the head of the Radio Television Digital News Association warned that products bearing the phrase “inflame the passions of those who either don’t like, or don’t understand, the news media”.

“At worst, they openly encourage violence targeting journalists,” executive director Dan Shelley wrote. “We believe they are particularly inflammatory within the context of today’s vitriolic political and ideological environment”.

Shortly thereafter, Mr Shelley wrote in an online post, he received an email from the retailer saying his warning had been “forwarded to the appropriate team to remove it”. The shirt has since disappeared from Walmart’s website and that of teespring.com.

“We are grateful for Walmart’s swift action, but dismayed that it, and anyone else selling the shirt, would offer such an offensive and inflammatory product,” Shelley said in a statement.

A Walmart spokesperson noted in a statement that the shirt came through a third-party vendor but confirmed that the item “clearly violates our policy”.

“We removed it as soon as it was brought to our attention, and are conducting a thorough review of the seller’s assortment,” the spokesperson said

The shirt appeared last year at rallies for Donald Trump’s presidential campaign. Mr Trump regularly excoriated journalists during those events, calling them liars and encouraging the crowd to jeer at reporters who had attended to cover his speeches.

He has continued to vilify the press during his presidency, regularly denouncing media organisations he views as antagonistic to his millions of Twitter followers. The President generated controversy for sharing a tweet of a train labelled “Trump” slamming into a figure with the CNN logo for a face.