Watch: 'Go to Auschwitz' at Trump rally

Unidentified man carrying Trump poster hurls abuse at reporter during Cleveland Trump rally.

Ari Soffer,

Trump rally in Cleveland
Trump rally in Cleveland

Video of a Donald Trump supporter telling a journalist and protesters to "go to Auschwitz" has gone viral, once more highlighting concerns over the populist GOP frontrunner's campaign.

The video, shot in Cleveland on Saturday during a Trump rally, shows an unidentified man turning towards a Dutch reporter and shouting "Go to Auschwitz! Go to f***ing Auschwitz!"

Someone behind the cameras then shouts "I got that on camera!"

The incident has been seized upon by Trump critics as further proof of the Republican candidate's worrying tendency to rally far-right and other extremists to his corner. Trump recently came under fire for hesitating to disavow support from notorious White Supremacist David Duke, and for a rally in which supporters were encouraged to raise their hands and pledge allegiance in what some critics claim bore the hallmarks of Nazi rallies.

For his part, Trump has rejected all such accusations, and the billionaire business man did eventually disavow Duke.

The weekend saw clashes at Illinois and Ohio as anti-Trump protesters disrupted his campaign events in those cities, clashing violently with supporters and the police.