German police said Saturday that they are pressing forward with deportation proceedings for a young man accused of planning a New Year's Eve terror attack on Cologne Cathedral. 

The Dortmund District Court had granted a deportation warrant for the 25-year-old man on Friday, according to a statement from the Cologne police.

Police said they would not comment further on the issue in their short statement on Saturday. Often when authorities in Germany seek a so-called deportation warrant, it means the suspect had entered German illegally.

The suspect, a Tajik national, was arrested on December 31 along with three others. 

The three other suspects had been released on New Year's Day, with police deciding to keep the 25-year-old in custody. 

Another 30-year-old Tajik suspect, who was arrested on Christmas Eve in the city of Wesel north of Cologne, also remains behind bars in Germany. Austria has issued a European arrest warrant for the suspect on terrorism charges, and extradition proceedings are still pending.

Authorities in Vienna said last week that the man, who German prosecutors also believe was something of a string-puller for a potential small terror cell, was thought to have connections to individuals they arrested around the same time. Those arrests coincided with tightened security meaures around St. Stephen's Cathedral in Vienna.   

What is known about the planned attack? 

German police believed attackers planned to use a car to attack the large crowds that gather outside Cologne's cathedral, which is right next to the central train station, every year around midnight on New Year's Eve.

German newspaper Die Zeit and others and other media reported that the suspects planning the attack were thought to be members of a branch of the "Islamic State Khorasan" group, also known as IS-K.   

IS-K is active in Central and South Asia, particularly in Afghanistan. In 2021, the group carried out a rocket assault on Kabul International Airport, leaving 170 Afghan civilians and 13 members of the US military dead.  

German police had boosted security measures around the cathedral prior to New Year's Eve, following rumors of an attack. Around 1,000 officers were deployed in order to ensure a peaceful celebration. 

In addition to terrorism fears, German authorities were also concerned about potential attacks on police and firefighters.

During New Year's Eve 2022, emergency personnel in Berlin, Düsseldorf and other cities were met with violence from belligerent people, often involving fireworks.  

wd/msh (dpa, AP)