BERLIN (Reuters) - A German federal judge issued an arrest warrant on Wednesday against a 19-year-old Syrian man detained on suspicion of planning a bombing attack, the Public Prosecutor’s Office (GBA) said in a statement.

Police detained the man, identified only as Yamen A. under German privacy laws, on Tuesday and prosecutors said they believe he had planned an Islamist-motivated bomb attack with the aim of killing as many people as possible.

He had been in contact online with jihadists including one who described himself as a “soldier of the caliphate”, a spokeswoman for the federal prosecutor’s office said.

Yamen A. was arrested in the northeastern town of Schwerin. Police searched his home and also those of other people not suspected of being directly involved.

The arrest comes one month before the first anniversary of an attack in Berlin by a failed Tunisian asylum seeker who killed 12 people by plowing a truck into a Christmas market.

Concrete blocks have been installed around Christmas markets at several central squares in the capital this year before the festive season opens in a couple of weeks.