BERLIN (Reuters) - Germany’s police union and women’s rights groups accused the authorities on Tuesday of playing down reports of harassment, sexual assault and even rape at refugee shelters because they feared a backlash against asylum seekers.

Laundry hung out to dry on a fence surrounding former U.S. army housing barracks used as a refugee registration center for the German state of Hesse in Giessen, 40km southwest of Frankfurt, Germany, September 10, 2015. REUTERS/Kai Pfaffenbach

Interior Minister Thomas de Maiziere called on Germans to avoid succumbing to a blanket suspicion of the hundreds of thousands of migrants arriving in the country, saying an unbelievable number of rumors were being spread on the Internet.

But police union chief Rainer Wendt said he believed that authorities in Germany’s federal states, which are responsible for housing asylum seekers, were playing down the problem of assaults on women in the shelters.

“It is understandable that there is the desire to calm things down politically,” Wendt told Reuters. But he, along with women’s groups, believed that ignoring the problem would be counterproductive. “There is a lot of glossing over going on. But this doesn’t represent reality,” he said.

With public opinion hardening on the refugee influx, German authorities appear anxious to avoid giving extreme-right groups any opportunity to stir up hostility towards migrants, many of whom are Muslims including those fleeing the Syrian civil war.

“There are an unbelievable number of rumors regarding this issue, which are being spread massively over social networks,” De Maiziere told a news conference.

“The federal authorities are investigating these resolutely and often the rumors are not true,” he said. “There are things worthy of criticism. But there is no reason for a general suspicion of refugees.”

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No comprehensive official figures are available on the extent of the problem at the shelters, which local authorities are setting to provide temporary accommodation around the country in places such as sports halls and empty office blocks.

But Wendt said the police were reporting cases to the state governments, which have their own interior ministers. These people should take note, he said: “The interior ministers would be well advised to have a look at their own reports to know what actually happens on our streets at night and in the shelters.”

Wendt said that a high number of cases went unreported as women rarely dared to file complaints with police or public prosecutors.

This is a general problem with sex crime, regardless of the community where it is committed, due to the victims’ feelings of fear and shame.

However, Barbara Helfrich of the charity Paritaetischer Bund in the central state of Hesse, said some women had come forward. “We have several trustworthy reports on sexual violence and assaults from victims, as well as advisory groups and NGOs,” she told Reuters.

In a recent open letter, several charities alleged crimes had been committed a city shelter in the state. “There are several cases of rape and sexual assault and increasingly even reports on forced prostitution,” the joint letter said, adding that these were not isolated incidents.

With men accounting for about 70 percent of asylum seekers, other groups across the country have demanded gender-segregated accommodation and safe zones for women.

At least 800,000 asylum seekers are expected in Germany this year, and Chancellor Angela Merkel’s popularity has fallen with polls showing many voters believe she is taking too soft a line on allowing them into the country.

The northern city of Hamburg recently confirmed eight cases of sexual assault in refugee shelters this year.

Tuelin Akkoc, spokeswomen for refugee affairs with the opposition Green Party in Hamburg, accepted that far-right groups might use such reports to turn sentiment against migrants. But she told Reuters: “That’s no reason to sweep this issue under the carpet. Right now is the time for the authorities to raise their voices in order to prevent extremist groups from dominating the debate.”