Players of Borussia Dortmund will attempt to set aside the shock from Tuesday night’s series of explosions that damaged their team bus when they face Monaco today.

The bus came under attack about six miles from the Signal Iduna Park match venue, 90 minutes before kick-off, as explosives police said were hidden in a nearby hedge went off.

Police called it “a targeted attack” and found a letter at the scene claiming responsibility for the attack.

That letter is now being examined as part of the police investigation, but German media reports the letter suggests possible Islamic extremist links to the attack.

Debris from the explosion injured Dortmund’s Spanish defender Marc Bartra who subsequently 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 was also wounded.

Fans already at the 80,000-capacity Signal Iduna Park were told to stay at the venue until it was safe to leave.

The stadium was later evacuated safely but police are preparing for a “large deployment” at today’s rescheduled game, while security at tonight’s other Champions League ties – Atletico Madrid v Leicester City and Bayern Munich v Real Madrid – is being stepped up.