Anti-Israel demonstrators made comparisons between the Israel-Hamas war and the Holocaust as thousands marched in London.
The demonstrators marched from Bank Junction to Westminster on Saturday, with many holding signs with the words "Free Palestine" and "End the siege".
Some protesters chanted: "One, two, three, four, occupation no more, five, six, seven, eight, Israel is a terrorist state."
Sections of the crowd also chanted "From the river to the sea, Palestine will be free" and "From London to Gaza, globalise the intifada". Jewish groups argue the phrase “globalise the intifada” is a call for the violence against Israel to be widened.
Several placards also made reference to the Nazis. One showed a Star of David symbol being pushed into the sea and around it were written the words ''The Final Solution?''.
Police said they were investigating the wording of a number of similar signs, including one showing a photograph Holocaust victims alongside one of Palestinians killed in the war.
Other placards stated: "Zionism = white supremacy" and "Israel's Gaza Holocaust”.
Former Labour leader Jeremy Corbyn and former shadow chancellor John McDonnell were among the speakers at the event. The pair called for an immediate ceasefire in Gaza.
The Metropolitan Police said that 13 protesters were arrested, mostly for offensive placards. Police said that one woman was arrested after the force's specialist Voyager CCTV monitoring team identified her as being wanted for an offence that occurred at a previous protest on October 28.
Before the march, police arrested a man on suspicion of a racially aggravated public order offence.
A spokesperson for Campaign Against Antisemitism (CAA) said of Saturday's march: "Comparisons between Israel and Nazis or the policies of the Jewish state and the Holocaust are clear breaches of the international definition of antisemitism.
"They show a woeful ignorance of history, insult the victims of the Holocaust and their descendants, diminish and trivialise the genocide of the Jews, and demonise the Jewish state.
"They are blatantly anti-Semitic rhetoric and underscore just how unpeaceful these weekly anti-Israel demonstrations have been.
We are appealing for the public's help to identify the woman below as part of an investigation into a placard carried at the protest earlier today. We would also appeal to the woman to come forward.— Metropolitan Police (@metpoliceuk) December 9, 2023
Anyone with information should call 101, providing the reference 4240526/23.… pic.twitter.com/hNYbVseHjd
"It is shameful that those Londoners brave enough to enter the centre of town have to bear witness to openly racist signage on their streets."
Karen Pollock, chief executive of the Holocaust Educational Trust, said on X/Twitter: “Saturdays in London.
“Signs comparing the Jewish State to the Nazis; signs with the 'Final Solution' - the Nazi euphemism for the murder of 6 million Jewish men, women and children; calls 'from the River to the Sea' - a genocidal call for the eradication of Israel. Peaceful.”
The march is the latest in a series of weekly protests called by the Palestine Solidarity Campaign and the Stop the War Coalition.