LONDON, Oct 4 (Reuters) – On Saturday, law enforcement in London detained several individuals for endorsing a prohibited pro-Palestinian organization during a protest that proceeded despite calls to cancel it following a lethal assault at a Manchester synagogue.

The violent incident on Thursday in the northern English city resulted in two fatalities, with police neutralizing the attacker, identified as a British citizen of Syrian origin. Authorities from counter-terrorism units indicated that the attacker might have been motivated by radical Islamist beliefs.

Despite pleas from both law enforcement and government officials to cancel Saturday’s protest, organizers proceeded with the event, originally planned before the attack, to demonstrate against the proscription of the pro-Palestinian group Palestine Action under anti-terrorism legislation.

STARMER CALLS FOR CALM

Calling for calm on X on Saturday morning, British Prime Minister Keir Starmer said: “I urge anyone thinking about protesting this weekend to recognize and respect the grief of British Jews.”

“This is a moment of mourning. It is not a time to stoke tension and cause further pain. It is a time to stand together,” he said.

Police arrested protesters in Trafalgar Square in central London as they wrote slogans on placards declaring support for Palestine Action, which was proscribed in July after members broke into an airbase and damaged military planes.

Hundreds gathered for the protest, applauding and cheering those arrested as they were carried through the crowd by police without resisting. Onlookers chanted “shame on you” at officers.

“I’m disgusted by the police actually, they shouldn’t be arresting non-violent protesters here,” said protester Angie Zelter. “We have a right to protest and Palestine Action is not a violent organization, should never have been proscribed in the first place.”

Six people were arrested separately after unfurling a Palestine Action banner on Westminster Bridge outside parliament.

SERIES OF PROTESTS

The demonstration is the latest in a series of protests, during which hundreds have been arrested for defying the ban which makes it an offense to show support for Palestine Action.

Police said Saturday’s protests would draw resources away from security they have tightened around synagogues and mosques following Thursday’s attack.

Defend Our Juries, which organized Saturday’s protest, has condemned the attack on the Jewish community in Manchester, and urged police to focus on that, not policing the demonstration.

Thursday’s attack followed incidents of antisemitic and Islamophobic hate in Britain this summer, and pro-Palestinian marchers have taken to the streets to denounce Israel, drawing criticism from some members of the Jewish community.

Jewish and Muslim communities in Britain have expressed fears for their safety.

Israel has waged war on Hamas in Gaza since the Palestinian militant group attacked Israel two years ago. U.S. President Donald Trump has urged Israel to stop its bombardment after Hamas said it was ready to release hostages and agreed to some aspects of a plan to halt the war.