The number of sex attacks in the no-go zone of Alexanderplatz, Berlin, has almost doubled over the past year.

Berlin police are becoming ever more concerned about the rising level of crime in the area around the Alexanderplatz metro station. Over the past year, almost all crime has gone up in the area including sex attacks which have gone from a total of 20 in 2016 to 36 in the first 10 months of 2017, Die Welt reports.

The largest rise has been the number of drug-related offences which has gone from only 165 in 2016 to 425 cases so far this year. The Berlin drug scene has seen dramatic growth, as a large number of asylum seekers, working with Arab criminal gangs, take to the streets to peddle drugs.

Some of the migrant dealers sell traditional drugs like marijuana, but authorities have warned of the growth in distribution of new synthetic drugs called “Bonzai” and “Spice”.

The two are labelled as synthetic cannabis and according to Berlin police many users have complained of vomiting for hours, cramps, and foaming at the mouth. Prolonged use of the substances could even prove fatal, the police said.

Man Who Came to Aid of Underage Girl Attacked in Berlin ‘No-Go Zone’ https://t.co/ukRH3DWjY5 — Breitbart London (@BreitbartLondon) November 10, 2017

Violent crime has also increased to 150 cases so far this year in the area. Last week, a 20-year-old man was a victim of violence after being attacked by a group of seven young men in response to him coming to the aid of a 14-year-old who was being harassed by another man.

Last month, the Berlin government vowed to take on the rising crime at Alexanderplatz by increasing the presence of police officers in the area.

While an increased number of officers may prove to alleviate some of the criminality in the area, some in the government are concerned following leaked audio from the police academy in the city revealed allegations that members of Arab clan gangs had infiltrated the Berlin police force.