Dresden, Germany (CNN) Anti-Islam protesters gathered Monday in the German city of Dresden, with some carrying banners with the names of those killed in the Charlie Hebdo attack in Paris.

It is the 12th march in Dresden called by the protest group Patriotic Europeans against the Islamization of the West, or PEGIDA, since October. Dresden police say the number of people attending these rallies has increased from an estimated 350 protesters on October 20 to 18,000 on January 5 and 25,000 people on Monday.

The PEGIDA movement emerged last year in the eastern German city. About 2% of Dresden's inhabitants are foreigners.

The group claims to have supporters in more than 30 German cities and 18 countries in Europe. A PEGIDA group in Norway has also called for demonstrators to gather outside the Town Hall in the capital, Oslo, to show support for the French and demonstrate opposition to what it calls the "Islamification of Norway."

In Dresden, organizers earlier announced that Monday's rally would commemorate the victims of last week's attacks in Paris

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Critics, however, say that protesters are taking advantage of the attacks to attract supporters and incite hatred against refugees and foreigners.

Request to cancel march denied

German Justice Minister Heiko Maas called upon the organizers to cancel the protests. In an interview with German newspaper Bild, he said, "The victims do not deserve to be abused by such agitators."

The head of Germany's CSU party, Horst Seehofer, told ARD Television: "I want to request those responsible ... that they cancel their demonstrations for the foreseeable future, especially at a time when the whole world is shocked about the events in Paris."

German Chancellor Angela Merkel, who has repeatedly voiced her disagreement with the PEGIDA movement in recent weeks, made similar demands.

A representative for PEGIDA in Dresden told CNN that the march would not be canceled.

"They are putting us on the same level as radical extremists," said Kathrin Oertel, one of PEGIDA's leaders. "We have the right to express our condolences to the victims of Friday's terror attack."

Oertel added: "We all think we are being neglected by our politicians."

She later told CNN that she does not want to be perceived as racist.

"Muslims are only a tiny fraction of the population, but they're so dominant in pushing for their demands that German culture is being pushed back," said Oertel. "We want to live peacefully with all immigrants here in Germany, but we as Germans demand that they assimilate themselves into our culture and that they live in accordance with our laws and don't build up parallel societies."

At a planned protest in nearby Leipzig -- organized by a group similar to PEGIDA -- protest organizers had agreed to a city ban on showing anti-Mohammed cartoons , but city authorities revoked their ban Monday following criticism that it limited free speech.

According to German wire service Deutsche Presse-Agentur, Leipzig city officials originally made the decision to ensure that the protests would remain peaceful. "After Paris, one must assume that Mohammed cartoons are meant to be a provocation," DPA quoted a city representative before the ban was revoked.

French cartoonists reacted to the German PEGIDA marches by publishing caricatures in which they ridiculed the protesters.

On Saturday, 35,000 people assembled in front of Dresden's landmark site, the Frauenkirche, to advocate for tolerance. Local politicians emphasized that they were open for a dialogue with PEGIDA protesters.

Counterprotests planned across Germany

Counterprotests against anti-Islam demonstrators were planned in Hanover, Düsseldorf, Hamburg, Munich, Dresden, Leipzig and Berlin.

On its Facebook page, the leftist group Dresden Nazifrei (Dresden free of Nazis) called upon its supporters to protest against the anti-Muslim demonstrators. The Dresden Nazifrei organizers wrote: "It is your decision to decide whether there will only be protests in hearing range and sight distance or whether we will try to do more."

Large numbers of police officers will try to keep anti-Muslim protesters and their opponents from clashing, with a heavier presence because of the Paris attacks.

"We have slightly increased the number of police officers involved," a police representative told CNN on Monday, refusing to give specific numbers ahead of the demonstration.

Later, police said that around 1,600 officers were involved on Monday. Some 8,700 people protested against PEGIDA in Dresden, according to police.

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German Interior Minister Thomas de Maiziere told CNN's Christiane Amanpour last week that he was "worried by this tendency" but that the significance of the protests should not be overestimated.

"It's new, it's concerning, but we should not be dominated by PEGIDA when we discuss our political agenda," he said.

On the other hand, he said protesters posed some questions that needed to be answered. "They ask: 'Is there an end of asylum seekers, how dangerous is Islam for our society, what about the fight against IS ( ISIS ) -- can this be successful?' These critical questions have to be faced, have to be answered," de Maziere said.

But he said he did not fear a rise of ugly nationalism in Germany again.

'We learned our lessons from the Nazi years'

"I'm confident we are strong," he said. "We learned our lessons from the Nazi years, and you can see it's very interesting that the organizations of PEGIDA; they know exactly where the red line is which they should not cross -- this makes me more skeptical but they know where the taboos are in Germany so I don't see a renewal of the NPD (the far-right National Democratic Party) -- it's less than in other European countries. And we are very well aware of it, and we will fight against every tendency."

Joerg Forbrig, a European analyst with the German Marshall Fund of the United States, told CNN that the PEGIDA movement had really only gained traction in the Dresden area, where its ideas had fallen on "particularly fertile soil."

"These protests are not so much fueled by fear of Islam and fear of Islamist attacks, but by frustration at the cost of reunification -- about the way they are being integrated and represented since the fall of the Berlin Wall," Forbrig said.

Dresden already had a well-established network of right-wing extremists before PEGIDA's emergence, he said.

"It's more a case of East Germans not entirely feeling at home in Germany," Forbrig said. "There is a feeling of second-class citizenship, and in order to be heard, many East Germans take to radical measures."

The movement was "basically a plea for more attention more than anything else," he said. "I think this movement has peaked -- I don't think that there is much more of a local and regional potential that this movement can exploit."

Forbrig stressed that there was a substantial counterprotest movement, with those protesters outnumbering PEGIDA supporters last week in Cologne by 10-to-1.

In fact, across Germany on Monday, more than 80,000 people protested against PEGIDA, according to the news agency DPA.

In her New Year's speech , Merkel addressed the issue of xenophobia, saying such demonstrations encourage the exclusion of people because of their skin color or religion.

Merkel urged people not to attend such rallies, where people have "hatred in their hearts," she said.

"We know the value of unity in our country," she said. "It is the foundation of our success."