Federal prosecutors said on Thursday that there is no evidence that the suspect temporarily detained participated in the Borussia Dortmund attack on Tuesday, German media report.

Police had temporarily detained a potential suspect after three explosions rocked the Dortmund team’s bus on the way to a match, injuring a player and police officer. Officers searched his apartment as well as that of another potential suspect, who was not detained.

But on Thursday federal prosecutors say that there was no evidence the man – who was reportedly a suspected Islamist – had participated in the attack.

Prosecutors have however applied for an arrest warrent for the 26-year-old Iraqi man, identified as Abdul Beset A., due to suspicions that he is a member of Isis and led a terror unit in Iraq.

The daily Bild said that police had had Abdul Beset A. under surveillance for several months and believed, based on tapped telephone conversations, that he might be hiding explosives in his flat.

However a raid on his home Wednesday turned up blank, the report said, adding that investigators were still pursuing leads to the attack in the extreme right and far-left scenes.

Investigators believe Abdul Beset A. joined Isis in Iraq in late 2014 and was the commander of a unit of around ten fighters.

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