A warrant has been issued for the arrest of a suspected Islamist militant detained in connection with the Dortmund bus attack, German prosecutors have revealed.

They said while there is no proof the man had taken part in the bombing of the football team's bus, which left one player injured, they suspect the man was a member of the so-called Islamic State extremist group in Iraq.

They said he had arrived in Germany in early 2016 via Turkey, and they believe he had been in touch with Islamic State members while in Germany.