Boris Johnson
Boris JohnsonReuters

Former British Prime Minister Boris Johnson on Saturday criticized antisemitic calls that were heard in the streets of London, during a mass pro-Palestinian Arab protest which took place during Armistice Day.

An estimated 300,000 marched through London on Saturday as pro-Palestinian Arab supporters made their latest mass call for a ceasefire in Gaza. Meanwhile, far-right demonstrators held a counter-protest.

Some 150 people from the mass protest were detained under public order legislation for wearing face coverings and setting off fireworks, while 82 counter-protesters were held to prevent them infiltrating the main march, according to a report in the AFP news agency.

The march, which was organized by the Stop the War Coalition, is the biggest yet in London since Hamas' attack against Israel on October 7.

Huge crowds waved black, red, white and green Palestine Liberation Organization (PLO) flags and held placards proclaiming "Stop Bombing Gaza", shouting "free Palestine", "ceasefire now" and "Israel is a terror state".

The Metropolitan Police said it was "actively seeking" two masked men pictured on the march wearing Hamas headbands, promising "proactive action when they are identified".

Antisemitic slogans were spotted among the placards, British media reported.

“Almost 80 years after the end of the Second World War it is shocking to hear nakedly antisemitic chants on the streets of London today,” Johnson wrote in a post on X on Saturday night.

“There are people who plainly want to ignore the Hamas massacre of October 7. They want to wipe Israel off the map. That is what they were chanting for today. They must not and will not succeed. I thank the police for all their efforts to keep people safe - but we must all do more, because an ancient hatred is rising again in Europe. It must be stamped out,” he added.

Police recently said that antisemitic hate crimes in London have soared amid the Israel-Hamas war. As Between October 1 and 18, there had been 218 antisemitic offences in London, compared to 15 in the same period last year.

In one incident, pro-Palestinian Arab activists vandalized a kosher restaurant in London.