Sikh man booted from Donald Trump rally for 'Stop Hate' banner

Donald Trump has again come under fire over comments made towards a Sikh protester during his campaign rallies.

While discussing the September 11 terrorist attacks and the San Bernardino shooting during a campaign event in Muscatine, Iowa on Sunday, a man in a red turban unfurled a sign that read: 'Stop Hate'.

At the time of the banner's unfurling, the crowd were chanting "USA, USA, USA."

During campaign events, an announcement is read asking Trump supporters not to harm protesters, but instead to alert security that a protester has been spotted by chanting "Trump, Trump, Trump".

It is believed the protesters were chanting "USA, USA, USA," to alert security to the banner's unfurling.

Once the chanting had quieted down, Trump pointed into the audience at the protester as he was being escorted.

"He wasn't wearing one of those hats was he?" Trump said.

However, US news and opinion blog Mediaite have suggested Trump was referring to whether the Sikh man was wearing a campaign cap which reads 'Make America Great Again', rather than the man's turban.

This is just the latest in a string of gaffes the presidential hopeful has made that have been perceived as racist.