Dortmund bus bomb: Iraqi suspect held after attack 'a member of IS'

German prosecutors say a man arrested after the bombing of a bus carrying the Borussia Dortmund football team is a member of Islamic State - but there was no evidence he was connected to the attack.

Federal prosecutors issued an arrest warrant against the 26-year-old Iraqi man, named as Abdul Beset A, who was detained on Wednesday. 

The prosecutor's office said the man was a member of the "foreign terrorist organisation" Islamic State in Iraq where he led a commando unit of 10 members that was involved in kidnappings, smuggling, extortion and killing. The suspect had arrived in Germany via Turkey at the start of 2016.

However, the prosecutor's office said there was no evidence he had taken part in the Tuesday attack in Dortmund.

The man will appear before a judge who will decide whether to approve the arrest warrant issued by prosecutors, which will allow the man to be held for longer than 24 hours.

"The investigations have so far resulted in no proof that the suspect had taken part in the attack," the federal prosecutor said in a statement.

Chancellor Angela Merkel on Wednesday said she was "horrified" by the "repugnant act", which Dortmund city's police chief Gregor Lange described as a "targeted attack" against the team, also known as BVB.

The roadside blasts left Dortmund's Spanish international Marc Bartra and a policeman injured, with the bombs "containing metal pieces" detonating minutes after the team bus set off to a planned Champions League game against Monaco on Tuesday night.

As fans of the two sides expressed solidarity in a packed stadium, the quarter-final, first leg match was held in the western German city 24 hours later, with Monaco claiming a 3-2 win.

Tuesday's explosives detonated minutes after the Dortmund team bus pulled away from the squad's hotel.

Bartra underwent surgery on a broken wrist after he was hit by flying glass, Dortmund president Reinhard Rauball said.

A policeman, who was on a motorcycle escorting the team bus, suffered trauma from the noise of the blasts, which shattered the bus windows.

"The bus turned onto the main road when there was a huge noise - a big explosion," Dortmund's Swiss goalkeeper Roman Burki told Swiss media.

"After the bang, we all crouched down in the bus. We did not know if more would come." Some players hurled themselves to the ground, he said.

As the squad geared up for kick-off Wednesday, Dortmund's chief executive Hans-Joachim Watze vowed that his side "will play not only for ourselves today. We will play for everyone... we want to show that terror and hate can never determine our actions".

Before the match began, fans chanted "Bartra! Bartra!", in support for the defender who was hurt.

Interior Minister Thomas de Maiziere, who attended Dortmund's match, said the "fascination" surrounding football drove terrorists to try to disrupt it.

"That's why it's right that we do as much as we can to protect it, and not allow criminals to take the fascination away from us."

But former German international Lothar Matthaeus said it was "irresponsible" to get the players to go through with the game so soon after the attack.

"From what I heard from team sources, many players didn't want to play today. But UEFA put on pressure and politicians urged Borussia Dortmund to counter terror," he told Sky news channel, referring to the European football federation.