The UN rights chief has said that anti-immigrant violence rocking Belfast and recent clashes with police in Southampton were "shocking", criticising "incitement" on social media and elsewhere.
Authorities in Northern Ireland have accused far-right activists - including US tech billionaire Elon Musk - of stoking anti-immigrant violence and divisions as rioters in Belfast torched vehicles and buildings late Tuesday, forcing families to flee their homes.
The disorder, sparked by a brutal knife attack allegedly committed by a Sudanese national, comes with tensions already high in the United Kingdom following skirmishes in southern England last week over the police handling of the murder of a white student by a British Sikh man.
"Dehumanisation of whole groups within a society is totally unacceptable and is frankly despicable," Volker Turk told reporters in Geneva on Wednesday.
"The violence that comes out as a result in... both Northern Ireland and in Southampton were really shocking," he said.
"Providers" on social media platforms, he insisted, must "take the responsibility seriously that dehumanisation, hate speech, violence and incitement to violence is unacceptable".
"We cannot tolerate this in today's world... The polarisation that we see is shocking."
UK watchdog warns over riot videos
Britain's media watchdog warned online platforms of the risk of stirring up violence and hatred as posts about Belfast unrest went viral.
"Ofcom has today written to online service providers operating in the UK about the increased risk of their platforms being used to stir up hatred, provoke violence and commit other offences under UK law, in the context of recent civil unrest in Belfast," the watchdog said in a statement.
Footage of the Belfast attack went viral on social media, with appeals for calm from police and lawmakers going unheeded in some areas of Northern Ireland.
Northern Irish political leaders and the police had urged people not to share the video, noting its "graphic nature would only serve to retraumatise those involved".
Liberal Democrat leader links Musk to riots
UK Liberal Democrat leader Ed Davey has accused “social media barons” and their algorithms of helping fuel violence in Belfast, urging the government to take tougher action against online platforms.
Speaking during Prime Minister’s Questions, Davey said on Wednesday extremists often exploit public grief and anger following serious crimes to spread hatred and violence, “aided and abetted by social media barons like Elon Musk and their divisive algorithms.”
“Does the Prime Minister agree this is not who we are as a country and that it is not free speech? It is controlled by tech billionaires and their algorithms,” he told MPs, calling for a crackdown on platforms such as X that he said were fueling violence and hatred.
Prime Minister Keir Starmer responded by pledging action against those responsible for deepening divisions while urging calm amid rising tensions in Northern Ireland.
“We will crack down on anyone who is fueling this division,” Starmer said.
Warning that Northern Ireland was entering “a very difficult situation,” the prime minister said he had spoken with senior political and policing figures, including the chief constable, the first minister and the deputy first minister.
“They are united in saying we should all be calling for calm,” he told the House of Commons.
