BORNHEIM, Germany (Reuters) - A western German town has barred adult male asylum seekers from its public indoor swimming pool after receiving complaints that some women were sexually harassed there.

Flowers and posters are placed in the square between the city cathedral and the railway station in Cologne, Germany, January 11, 2016, where the vast majority of dozens of New Year Eve assaults on women took place. REUTERS/Wolfgang Rattay

It was the latest sign of social tensions related to the arrival last year of 1.1 million migrants in Germany, followed by sex assaults on women by young male asylum seekers and migrants during New Year’s Eve celebrations in the city of Cologne.

The deputy mayor of Bornheim, a town of 48,000 some 30 km south of Cologne, said on Friday that a difficult decision was taken to send a clear message that breaching German cultural norms was a red line that should not be crossed.

“There have been complaints of sexual harassment and chatting-up going on in this swimming pool ... by groups of young men, and this has prompted some women to leave (the premises),” Markus Schnapka told Reuters.

“This led to my decision that adult males from our asylum shelters may not enter the swimming pool until further notice.”

He did not say how the ban would be enforced. German media say asylum seekers, who get no funds from the state, must present an identification document to be admitted to pools at a discounted rate.

Schnapka said his town had begun a campaign in local asylum seekers’ shelters to teach the occupants about gender equality and respect for women.

The gang attacks on women outside Cologne’s historic cathedral on the Rhine river deepened public doubts about Chancellor Angela Merkel’s open-door policy toward refugees fleeing conflicts in the Middle East and about Germany’s ability to integrate the mainly Muslim and Arab newcomers.

Police investigations into the incidents of sexual molestation are focusing on 19 suspects, including 10 asylum seekers and nine illegal migrants thought to be from North Africa. Police said the suspects came from outside Cologne.

On Thursday, a carnival parade planned for next month in Rheinberg, a town north of Cologne, was canceled after organizers said they would not be able to provide a security plan for the event on Feb. 8 as required by police.

German media reports said the decision arose partly from the fact that the parade route would have run near an asylum shelter with 500 residents. Rheinberg Mayor Frank Tatzel denied this when contacted by Reuters.

Merkel is now under increasing pressure to stem the flow of migrants coming to Germany. Several thousand continue to stream in every day and there has been a backlash by right-wing nationalist groups.