After an adolescent who pledged allegiance to terror group Isis attacked rail passengers with an axe on Monday, the Federal Office of Criminal Investigations (BKA) warned that further attacks on trains are possible.
In an internal report seen by Focus magazine, the BKA assess the risk of an attack on trains as “high” saying that “at any time an attack could take place.”
Threats against rails services and train stations “must be treated with special importance.”
The report also warned of an increased risk of violence against asylum seekers by the far right in the wake of the attack.
The German Police Union (DpolG) also called for the police presence on trains to be beefed up in the wake of the attack, which left four people seriously injured.
Complaining that the police presence at train stations has been severely cut down in recent years, the chairman of the union Ernst Walter claimed that “if we continue to be pulled back from these areas we won't have a means of countering these attacks.”
“Rail journeys would therefore come with an incalculable risk.”
Walter further called on the government to increase the presence of security cameras in stations and on trains and to put police officers inside trains.
The axe attack, which took place outside the town of Würzburg, was not the first time that a radicalized individual attacked people on a train in Europe.
In August 2015, a Moroccan man armed with an assault rifle and a pistol opened fire on a train travelling from Amsterdam to Paris.
Authorities in Germany have warned repeatedly over recent months that there risk of a terrorist attack in the country is high and two major events - a football match in Hanover and New Year's celebrations in Munich - have been cancelled due to terrorism fears.
Government officials have also stressed that the recent influx of refugees has not increased the likelihood of terrorist attacks in Germany.