German police have detained a suspect with “Islamist links” following a bomb attack on the bus of the Borussia Dortmund football team.
Prosecutors are treating the blasts as a terrorist attack but say the precise motive is unclear at present.
Prosecutors also said one of the three explosive devices contained metal strips and a piece of shrapnel had embedded itself in the headrest of one of the seats on the team bus.
Three copies of the same hand-written letter were found near the site of the blasts, indicating that the attacker had links to so-called Islamic State.
The letter demanded the withdrawal of German tornado reconnaissance jets from Syria and the closure of the US Ramstein air base in Germany.
A spokeswoman for Germany’s federal prosecutor, Frauke Koehler, said: “Two suspects from the Islamist spectrum have become the focus of our investigation. Both of their apartments were searched, and one of the two has been detained.”
The text is being analysed to see if it is authentic.
A second letter was published online, in which left-wing extremist groups claimed to have carried out the attack, but prosecutors had reason to believe this letter was not authentic.
Spanish international Marc Bartra underwent an operation after breaking a bone in his wrist. No other players were hurt, but a police officer on a motorbike escorting the bus suffered trauma from the noise of the explosions.
Several reports said the explosives had been hidden in a hedge.
Dortmund goalkeeper Roman Burki told Swiss news outlet Blick that the bus had turned on to the main road when there was a loud noise.
The players ducked to the floor of the bus, not knowing if there would be more blasts, he said.