BERLIN (Reuters) - Germany’s highest court has issued an arrest warrant for a 17-year-old Iraqi citizen suspected of planning an Islamist attack in Germany or Britain, the federal prosecutor’s office said in a statement on Thursday.

The young man, who was first detained on Feb. 13 by local authorities in Frankfurt, had stockpiled a large number of powerful fireworks in his apartment in the German state of Hessen, and planned to extract their explosive powder.

Prosecutors said the suspect, identified only as Deday A. in line with German privacy rules, is also suspected of being a member of the jihadist group Islamic State.

The Iraqi suspect was first detained and then arrested in Frankfurt, but the investigation was later elevated to the chief federal prosecutor’s office given the serious nature of the allegations.

The federal arrest warrant lays the groundwork for formal charges to be filed after further investigation.