The police have managed to trace the calls for 4 false bomb alarms and 1 poisoning back to one Luxembourgish prisoner in Nancy. Pictured: the central train station in Luxembourg City, one of the locations that received a bomb threat. Maison Moderne

 The police have managed to trace the calls for 4 false bomb alarms and 1 poisoning back to one Luxembourgish prisoner in Nancy. Pictured: the central train station in Luxembourg City, one of the locations that received a bomb threat. Maison Moderne

Four false bomb threats were made to the police over the past 2 months: Utopolis and Auchan at Kirchberg on 23 March; Globus in Bettembourg on 20 April; the CFL train station in Luxembourg City on 30 April. The City Concorde in Bertrange received a threat of poisoning on 27 April.

A joint police investigation found that all the calls were made from the same mobile phone, which could be traced back to the prison in Nancy-Maxéville in France, according to a statement issued by the public prosecutor’s office on Wednesday.

The suspect is a 56-year-old man, a Luxembourg national, who has already been sentenced in Luxembourg. He is currently serving a sentence in France until 2019.

The next step in the police inquiry has to establish the motives of the suspect. After police questioning, French authorities will likely receive a request for a European arrest warrant.