The media regulator has launched an investigation into comments made by the Channel 4 News presenter Jon Snow, who said of a pro-Brexit protest that he had “never seen so many white people in one place”.

Ofcom said it had received 2,644 complaints about the comment, which Snow made during a live broadcast outside the Houses of Parliament on 29 March as pro-Brexit protesters gathered in Westminster on the day the UK was meant to leave the EU.

While wrapping up the programme, Snow said: “It’s been the most extraordinary day. A day which has seen … I have never seen so many white people in one place, it’s an extraordinary story. There are people everywhere, there are crowds everywhere.”

Ofcom will also investigate comments made by Nigel Farage about Snow’s remark. The watchdog said it had received five complaints after the former Ukip leader told LBC radio that Snow “should be attacked without doubt” for making the statement.

Asked by the former Labour spin doctor Alastair Campbell, who appeared alongside him on the radio show, why Snow deserved to be attacked, Farage said: “Because of his terrible condescending bias, but that’s a separate issue.” He later clarified during the same programme that he meant a verbal attack, not a physical one.

An Ofcom spokeswoman said of both incidents: “We’re investigating whether comments made by the presenters on these programmes broke our rules on offensive content.”

Channel 4 News later apologised after Snow’s comments drew criticism. In a statement, the broadcaster said: “This was an unscripted observation at the very end of a long week of fast-moving Brexit developments.

“Jon has covered major events such as this over a long career and this was a spontaneous comment reflecting his observation that in a London demonstration of that size, ethnic minorities seemed to be significantly under-represented. We regret any offence caused by his comment.”