The CCTV footage, filmed in the early hours of October 27th, shows a young woman walking casually down the stairs of the Hermannstrasse underground station.

A young man then walks up behind her, followed by three people who appear to be his friends. Seemingly out of nowhere, he kicks her in the back, sending her tumbling down the stairs until she lands face first on the platform below.

All the men then walk away after the scene, leaving the woman lying in a heap on the floor.

Police say there is no known reason for why the man acted as he did.

They have also not provided any information on the current condition of the 26-year-old woman.

Authorities are now searching for witnesses who may have been in the station or its vicinity on the night of October 26th to 27th and who might be able to provide further information on the attacker.

Despite the brutality of this crime, assaults on Berlin’s public transport network have been on the decline for years, Tagesspiegel reports.

Whereas in 2010, 2,708 assaults were recorded in stations and on trains and buses, in 2015 that number had dropped to 2,296.

Up until September 2016, 1,690 assaults had been recorded on public transport.