Posters advertising a Holocaust memorial event have been daubed with graffiti including the words "liars" and "killer".
The Metropolitan Police said the incidents, which took place in Stratford, east London, were being listed as a "hate crime", and said officers in Newham were investigating.
Newham Council received pictures of the offences - involving three posters publicising the council's Holocaust memorial day event - through social media.
Meanwhile, Chief Constables across the country are reviewing how to strengthen the protection of their officers and the Jewish community in the light of the Paris terrorist attacks.
Assistant commissioner Mark Rowley, the national policing lead for counter-terrorism, said the attack on a kosher supermarket in the French capital and anti-semitic rhetoric from extremists had led to a "heightened concern" about the risk to the Jewish population in the UK.
Sir Robin Wales, Mayor of Newham, described the incidents in east London as "despicable".
He said: "This despicable and cowardly hate crime is an assault on the values of decency and mutual respect which the vast majority of us share.
"This outrage underlines not only the importance of keeping the memory of the Holocaust alive but of standing up to intolerance and hatred at every opportunity.
In pictures: Extremists in the EU
In pictures: Extremists in the EU
1/6 France: Marine le Pen
Marine Le Pen, 45, took over the Front National (FN), the party that her father founded, in 2011. He himself described her as “a big, healthy, blonde girl, an ideal physical specimen." She claims to have cleaned up the FN and succeeded in pushing her anti-European, anti-euro and anti-immigration agenda into the EU political mainstream
2/6 Germany: Udo Voigt
He will be the first German neo-Nazi to enter the European Parliament. The former army officer, born in 1952, was jailed in 1995 for inciting racial hatred. Formerly the leader of the far right National Democratic Party (NPD), Voigt was convicted in 2009 after he was caught handing out flyers at the World Cup which argued that a black player was not entitled to play for Germany, whose national team – the literature argued – should be made up only of white players.
3/6 Denmark: Morten Messerschmidt
Leader of the Danish People’s Party, which won 27 per cent of the vote. His party has rammed 20 laws relating to immigrants and asylum-seekers through the Danish parliament, giving it the most anti-foreigner legislation in Europe. His party calls Islam “a fascist ideology” and rails against “East European criminal gangs”. One party strategist said “blood ties” to Denmark should be required for citizenship, though the statement was quickly retracted.
4/6 Hungary: Krisztina Morvai
A senior member of Jobbik, the anti-Semitic and anti-Roma party on Hungary’s far right wing. In 2009, she attracted international publicity after declaring: “So-called proud Hungarian Jews should go back to playing with their little circumcised dicks.” In 2009, she cancelled an interview with a British newspaper, declaring in tones of outrage: “I am a decent politician and the mother of three children, yet you in the west keep portraying me as a Nazi and a Fascist.”
5/6 Italy: Mario Borghezio
MEP for Italy’s notoriously racist Northern League, he has relentlessly attacked the nation’s first black cabinet minister, Cecile Kyenge, minister for integration, claiming she would import ‘tribal traditions’ into the Italian government. Other elected members in the party called her “an orang-utan” and suggested that someone should rape her, so she would understand how the victims of Somali rapists felt. He attracted attention by lobbying for the creation of an EU archive of UFO sightings.
6/6 Greece: Eleftherios Synadinos
Fabulously mustachioed retired lieutenant-general in the Greek army, he was one of Golden Dawn’s top candidates in the European elections, at which the overtly neo-Nazi party obtained more than 9 per cent of the vote. With its black-shirted assault squads, the Hitler photos and the party’s swastika-inspired logo, it has been accused of being a criminal organisation. Its website declares: “We aren’t the quiet birds of peace time, we are birds of the storm and the hurricane.”
"Newham Council will work with our police partners to bring those responsible to justice."
The graffiti, which is being treated as racially aggravated criminal damage, has already been removed from the three sites around the Stratford area, the council said.
The posters, which are on display at 43 sites across the borough, are advertising the council's Holocaust memorial day event on Tuesday January 27 at Stratford Town Hall.
The council said police are checking the borough's CCTV footage to try and identify those responsible, and council officials will be monitoring all advertising boards in case of further offences.
Resident James Tattle reported one of the incidents to Newham Council on Twitter.
He said he was "repulsed" by what he saw.
"I recently noticed the posters promoting the Holocaust Memorial Day event, I thought it was great that an event was happening locally to mark the occasion.
"I was utterly repulsed, and saddened, to see one of the posters had been defaced.
"I couldn't believe that anyone would stoop so low as to scrawl that graffiti - not something I expect to see in London in 2015," he said.
The racially aggravated criminal damage was found in three locations: two in High Street, Stratford, and one in West Ham Lane, near Stratford Park, the council said.
Police said enquiries are ongoing and no arrests have been made at this stage.Reuse content