Five people have been arrested - including two for chanting slogans involving the word "intifada" - during a protest by pro-Palestinian demonstrators outside the Ministry of Justice in London.
The arrests come after both the Metropolitan Police and Greater Manchester Police (GMP) said anyone chanting slogans such as "globalise the intifada" would face arrest.
In a post on social media on Wednesday, the Met said two people "who shouted slogans involving calls for intifada were arrested for racially aggravated public order offences".
A third person was arrested at the time for "obstructing" officers as they tried to make those original arrests.
The Met said the demonstration - which was estimated to have drawn a crowd of around 100 people - had concluded and they had made two further arrests, one of which was for a racially aggravated public order offence.
The arrests came after the UK's Chief Rabbi Ephraim Mirvis welcomed the decision for both the Met and GMP to change their approach and arrest anyone shouting slogans such as "globalise the intifada" in the wake of the terrorist attacks at Sydney's Bondi Beach and at the Heaton Park Synagogue in Manchester in October.
Mirvis described the move by the police forces as "an important step towards challenging the hateful rhetoric" seen on Britain's streets.
Met Commissioner Mark Rowley and GMP Chief Constable Stephen Watson issued a joint statement addressing the chants.
"We know communities are concerned about placards and chants such as 'globalise the intifada' and those using it at future protest or in a targeted way should expect the Met and GMP to take action," they said.
"Violent acts have taken place, the context has changed - words have meaning and consequence.
"We will act decisively and make arrests."
In their statement, Rowley and Watson said due to the "escalating threat," both forces will now "recalibrate to be more assertive".
"We have consistently been advised by the (Crown Prosecution Service) that many of the phrases causing fear in Jewish communities don't meet prosecution thresholds.
"Now, in the escalating threat context, we will recalibrate to be more assertive."
While the move was welcomed by Jewish groups, Ben Jamal from the Palestine Solidarity Campaign said it infringes on the right to protest.
"The statement by the Met and GMP marks another low in the political repression of protest for Palestinian rights," he said.
"The police have not consulted with the Palestine coalition who organise the major protests in London, nor representative groups of the Palestinian community in Britain, before making this far-reaching statement on our rights.
"The Arabic word intifada means shaking off or uprising against injustice. It came to prominence during the first intifada which was overwhelmingly marked by peaceful protest that was brutally repressed by the Israeli state.
"The implication that slogans used to support the liberation of the Palestinian people are only open to interpretation by groups who have maintained complicit support for Israel's oppression of the Palestinian people and denial of their rights is deeply problematic."