Police stand at Cologne Central railway station on October 15, 2018 in Cologne, Germany. The German police ended a hostage-taking in Cologne Central Station on Monday and freed a woman from the violence after hours of tension. (Xinhua/Ulrich Hufnagel)

The German police ended a hostage-taking in Cologne Central Station on Monday and freed a woman from the violence after hours of tension.

The hostage taker was seriously injured and his victim, a teenager girl, suffered only minor injuries, the local police said on Twitter.

The police said the perpetrator was under control, while the crime site remained locked, as the police were making extensive investigative measures.

The perpetrator took the hostage at noon at a pharmacy inside the Cologne Main Station building. After a first contact with the man, the police prepared the access and finally entered the pharmacy.

The police operation brought the rail traffic around the central hub Cologne almost to a standstill. The station was evacuated, trains were widely diverted and some trains ended prematurely.

First emergency calls from the station reached the police at noon, and later the area around the station was secured and evacuated. And the police on Twitter asked people to avoid the area.

Then the special task forces made contact with the hostage taker, however, nothing was known about the man's demands.

During the hostage-taking, an injured girl was taken to hospital from the station. Whether this injury is in connection with the hostage-taking still has to be investigated, the local Focus Online news quoted a police spokeswoman as saying.

Police quoted by the Cologne City Information daily said a couple were involved, and the man argued with the woman in a McDonald's restaurant, before holding her in a pharmacy at the station.

The Cologne Central Station is one of the most important railway junctions in Germany and western Europe.