By Justin Huggler, Berlin 5:04PM GMT 18 Feb 2016

Frequently the young men are arriving appear disproportionately as offenders, Ralf Jäger, the state interior minister, says

Germany’s most populous state has said it will not accept any more asylum seekers from Morocco, after migrants from the country were identified among suspects in the Cologne sex attacks.

The government of North Rhine-Westphalia, where Cologne lies, said federal authorities had agreed not to send any more Moroccans to refugee accommodation in the state.

There is no suggestion that Moroccans will be blocked from entering the state if they enter.

While Germany’s federal police say there is no link between crime and refugees from war-torn countries like Syria, there has been a sharp rise in crimes committed by North Africans.

Police in North Rhine-Westphalia say gangs of North African thieves and pickpockets are operating in the cities.

The move by the state came as Austria imposed strict quotas on the number of asylum seekers it will allow to cross its borders each day.

In future, only 80 people a day will be allowed to apply for asylum in Austria, and a further 3,200 will be allowed to cross through the country on their way to Germany.

Johanna Mikl-Leitner, the Austrian interior minister, said the move was part of a deliberate attempt to block the Balkan route across Europe to migrants.

"It is important each country along the Balkan route places restrictions on its borders,” Ms Mikl-Leitner said.

“This domino effect is all the more effective if it is coordinated.”

But the plans would be "plainly incompatible" with European Union laws, European migration commissioner Dimitris Avramopoulos said in a letter to Ms Mikl-Leitner.

"You plan to apply a ceiling for the number of asylum applications which Austria is prepared to accept," Mr Avramopoulos said in a copy of the letter obtained by AFP. "Such a policy would be plainly incompatible with Austria's obligations under European and international law."

Several countries are pressing to close the route to migrants.

Austria, Macedonia, Serbia, Croatia and Slovenia said on Thursday they have set up a joint registration point for asylum seekers on Greece’s northern border.

They plan to transfer refugees north to Germany and Austria in “controlled transport” to prevent them travelling independently.

“Our goal is that the refugees' transfer from Greece to Macedonia, and later to Austria, is as painless as possible, Vlado Dominic, the Croatian police chief said.

Meanwhile, women asylum seekers in Cologne have complained they are victims of sexual harassment.

In an open letter, women staying at a gym being used as a temporary refugee shelter said security guards had filmed and photographed them while they were showering, and pressured them for sex.

“For us, the gym is no shelter. It is a prison,” they wrote.

One Syrian woman said a security guard had asked her for sex.

“When I told him I was involved with some one and wasn’t interested, he told me I’d be thrown out,” she said.

“I am appalled at these allegations. I am sure they are unfounded,” Bernhard Deschamps, manager of the company responsible for the site, said.

The Cologne authorities said they would investigate the allegations.

No more asylum seekers from Morocco, says Germany's most populous state citing crime