Channel 4 News presenter Jon Snow has been cleared by the media regulator after saying he had “never seen so many white people in one place” while describing a pro-Brexit protest – partly because video footage of the crowd did indeed show that the protesters were overwhelmingly white.

The journalist was reporting from outside parliament on 29 March, the day Britain had been due to leave the EU, when he made the unscripted comments, prompting thousands of complaints to Ofcom that his remarks had been racist or offensive.

“It has been the most extraordinary day,” he said at the end of the hour-long programme. “A day which has seen – I’ve never seen so many white people in one place. It’s an extraordinary story. There are people everywhere, there are crowds everywhere”.

Members of the public variously complained to Ofcom that Snow was implying that differing views on Brexit are based on race; implied a potential link between Brexit supporters and white supremacists; encouraged racial tensions; or was biased, given that the racial background of participants in similar pro-remain marches had not been referred to in the same way.

Many of the complaints against Snow’s comments had been spurred by a social media campaign among pro-Brexit campaigners. Channel 4 later issued a statement apologising for any offence caused but stood by their presenter. They insisted that Snow’s comment was justified under the broadcasting code as it was “reflecting his observation that in a London demonstration of that size, ethnic minorities seemed to be significantly under-represented”.

In its ruling Ofcom said that it “acknowledged the large number of people protesting and in the crowd appeared to be predominantly white” and sufficient context had been provided.

However, it warned Channel 4 needed to be careful, given Snow’s comments followed a discussion involving the writer Will Self, who had made reference to “ethnic nationalism” in the context of Brexit, which could have implied “there was a link between Brexit supporters and white supremacists”.

“In the context of the current volatile public discourse surrounding Brexit, particular care is needed to fully contextualise any ambiguous statements in programmes on sensitive issues that have the potential to cause offence to audiences,” the broadcaster said.

In a separate ruling, Ofcom also cleared Brexit party leader Nigel Farage of using his LBC show that same evening to say that “Jon Snow should be attacked” for his comments on the crowd being white. Farage had swiftly made clear on the same programme that he meant that Snow should only be “verbally attacked” for allegedly showing bias.