Activists waving Palestine flags, chanting and lighting flares converged on Queen Victoria Street for a planned march towards Parliament Square as they continue to call for a ceasefire in war-torn Gaza.
Some activists wearing masks of Israeli Prime Minister Benjamin Netanyahu were seen holding bloodied dolls up in the air in a bid to highlight the innocent lives being caught up in the Middle East war.
Ahead of today's march, the Government has also advised that anyone who yells 'Jihad' while protesting should be arrested on sight.
Around 1,700 police officers from the Met and other UK forces have been mobilised amid fears the escalating tension in Yemen will bring more activists to the streets of the capital.
A 'significant policing presence' will be seen this weekend, with the Met also drafting officers in from outside of London. Activists who 'intentionally push the limit' on placards and slogans are warned they face arrest.
Home Secretary James Cleverly said he had been briefed by the Met's commissioner Sir Mark Rowley on plans to 'ensure order and safety' during the protest.
'I back them to use their powers to manage the protest and crack down on any criminality,' the MP said.
'Anyone of reasonable mind would know this and I am strongly of the view that people who are chanting 'jihad' should be arrested. I think the scale of pressure this is putting on the police is really concerning.
'The build-up of rest days are going to have to be paid back and it will come out of other frontline policing priorities.
'If it's really the case that this drumbeat of mass protest is going to continue then we risk the public being significantly more exposed to crime as a result of it.'
There have been repeated examples of placards, banners and other items being carried or worn, or statements being chanted, that have 'crossed the line' into religiously or racially aggravated offences or crimes under the Terrorism Act, the force added.
Lord Walney insisted he is not claiming every mass protest 'should come with a price tag' but said it was 'reasonable' to look for a way to tackle the huge policing cost.
By mid-December, the Metropolitan Police alone had deployed up to 2,000 officers to the capital every weekend since Hamas invaded to tackle the marches, which is said to have cost the tax payer an estimated £20 million.
Appearing before MPs last month, the force's assistant commissioner Matt Twist warned that the weekly Saturday marches had caused the 'greatest period of sustained pressure on the Met since the Olympics in 2012'.
He added that 28,000 officer shifts had been dedicated to the events and a further 1,600 borrowed from other forces. A total of 5,500 rest days were axed with 6,000 hours used to investigate alleged hate crimes.
According to the Telegraph, an extract submitted read: 'The number of marches being organised around the Israel-Hamas conflict, the scale of these marches, and the behaviour of some protesters means that a great amount of police resource is being directed to these protests.'
It went on to say that 'when groups run so many mass protests, the authorities should consider whether organisers should be asked to contribute to policing costs'.
https://www.dailymail.co.uk/news/article-12958941/More-200-000-Pro-Palestinian-marchers-set-descend-London-today-Yemen-airstrikes-expected-raise-tensions-1-700-police-mobilised-government-advise-saying-yelling-Jihad-arrested-sight.html