A union leader was attacked after speaking at a counter-protest to a rally in support of Donald Trump and jailed far-right leader Tommy Robinson.
Steve Hedley, Senior Assistant General Secretary of the National Union of Rail, Maritime and Transport Workers (RMT), was assaulted by supporters of the US president and Robinson, according to anti-fascism campaigners Hope Not Hate.
The perpetrators could not be immediately verified independently.
Witnesses said a mob ambushed two men at the Westminster Arms pub in Central London on Sunday afternoon in a targeted attack.
“They (the attackers) knew what they were doing,” one witness, who asked not to be named, said.
Smashed glass was strewn across the pavement outside the establishment on Storey’s Gate, and pictures showed Mr Hedley with a bandaged head and bloodied face.
Scotland Yard feared violence ahead of the rally in support of Mr Trump during his visit and 35-year-old Robinson, who was jailed for 13 months for contempt of court after filming people involved in a criminal trial and broadcasting the footage on social media.
The march to Downing Street was kept at a distance from the counter-protest in Parliament Square, the day after an estimated 100,000-plus rallied through London in opposition to the US president.
Mr Hedley was among those to speak at the counter-protest.
Some outside Downing Street waved “Britain Loves Trump” placards, wore Mr Trump’s red Make America Great Again caps and cheered at mentions of the US leader, but the main focus was Robinson, real name Stephen Christopher Yaxley-Lennon.
The Metropolitan Police said Trump supporters were due to leave the US Embassy and meet Robinson fans on the way to Whitehall, but ordered both must depart Temple Place and follow a strict route after “serious violence” at a June 9 march resulted in five officers being injured.
A small group on Saturday breached the order by starting at the US Embassy, pictures on social media showed.
Images also showed minor clashes between supporters and opponents in Parliament Square, and officers at the scene said cordons had been bolstered after breaches from the right-wing group.
The Met could not immediately comment on Mr Hedley’s attack.
The force said a total of 12 people have been arrested as part of the demonstrations.