Police have violently clashed with pro-Palestinian protesters close to Downing Street as thousands descended on central London with banners and posters to call for an end to the conflict in Gaza.
Some protesters were chanting, “From the river to the sea, Palestine will be free”, despite controversy around the slogan’s meaning.
Outside the gates of Downing Street near the Cenotaph, officers appeared to be detaining someone before demonstrators began grappling with them.
Punches and kicks were thrown, and police ordered people to move away.
One man was taken to the floor and carried away to chants of “let him go” from other protesters. Cries of “Allahu akbar”, the Arabic phrase for “God is great” also rang out.
The Metropolitan Police said one person has been arrested after a police officer was assaulted.
The force added an officer was being taken to hospital following the incident on Whitehall.
Ahead of the march, the Met said it expected up to 100,000 people at the protest but warned officers would intervene if any demonstrators used the word “jihad” in chants.
Kyle Gordon, who is leading the force’s command team, told a press briefing: “If somebody is calling for jihad specifically against Israel, the officers will intervene, gather the information, report it back to us and we’ll be working with colleagues, (from counter-terrorism) about what the best course of action is.”
It comes after Met commissioner Sir Mark Rowley differed with ministers this week over how to police pro-Palestine protesters using the phrase.
Last week, police officers made ten arrests for offences involving launching fireworks, public order and assaulting an emergency service worker.
As the demonstration wound to a close, fireworks were “launched at officers from within the crowd” at Trafalgar Square, Metropolitan Police said. The week before, 15 people were arrested while nine police officers were injured.
Transport for London also suspended a Tube driver who appeared to lead a “free, free Palestine” chant on a Central Line train, a decision backed by Sadiq Khan.
On Friday, Mr Khan and some Labour MPs called for a ceasefire in Gaza.
“Many Londoners like me have watched the absolute horror at the death and suffering in Israel and Gaza,” Mr Khan said.
“I join the international community in calling for a ceasefire. It will stop the killing and would allow vital aid supplies to reach those who need it in Gaza.”
He was supported by several Labour MPs, including Dawn Butler and Marsha de Cordova.
Brent Central MP Ms Butler said: “I agree with Mr Khan’s statement. An immediate ceasefire is necessary and a freeing of all hostages.”
On Saturday, former Labour leader Jeremy Corbyn addressed pro-Palestine protesters in London.
Speaking on a stage in Parliament Square, he said: “The world’s nations voted at the United Nations last night in the General Assembly by an overwhelming majority to demand a ceasefire.
“It’s not much to ask, a ceasefire when children are being killed by weapons coming through the rooms of their homes.
“It is in eternal stain that the British Government abstained on that vote.”