Police will do "everything humanly possible" to ensure Borussia Dortmund's fixture against Monaco this evening takes place safely in the wake of the bomb attack on the German side's team bus.

Three explosions occurred as the Dortmund squad were travelling to the Signal Iduna Park stadium for Tuesday's Champions League quarter-final first leg and the game was subsequently postponed and rescheduled to be played on Wednesday.

The attack left Dortmund defender Marc Bartra requiring surgery on a broken bone in his wrist.

Borussia Dortmund bus explosion Show all 20 1 /20 Borussia Dortmund bus explosion Borussia Dortmund bus explosion Borussia Dortmund bus explosion A number of Dortmund players have admitted they have struggled to cope following a bomb attack on their team bus, which left defender Marc Bartra hospitalised. Bongarts/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Dortmund player was injured following explosions near the team bus ahead of the Champions League quarterfinal match against Monaco. Bongarts/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion North Rhine-Westphalia police spokesman Gunnar Wortmann told The Associated Press Tuesday that there were "three explosions near the team bus as they left the hotel to go to the stadium" and that "there was one player injured inside and damage to a window." AFP/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Dortmund said the player was "in safety" and that "there is no danger in and around the stadium." AFP/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion In a statement, police say there was an explosion after 7 p.m. local time. AFP/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion The chief executive of a German soccer team Borussia Dortmund says player Marc Bartra was injured on the arm and hand when three explosions went off near the team bus. AFP/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Dortmund Chief Executive Hans-Joachim Watzke said the injuries to the Spanish defender Tuesday night are "nothing life-threatening." Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Dortmund police spokeswoman Nina Vogt says investigators do not yet know the source of the explosions that went off as the team was preparing to leave their hotel for a match against Monaco. Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion The chief executive of German soccer team Borussia Dortmund says police informed him that the explosives that went off near the team bus were hidden by the exit of a hotel and detonated as the bus passed. Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Borussia Dortmund goalkeeper Roman Buerki says the team bus had just pulled out of a hotel driveway at about 7:15 p.m. when it was rocked by an explosion. Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Buerki told Swiss daily Blick on Tuesday night that "there was a huge bang, literally an explosion" that sent glass flying about. Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Bongarts/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Police in the German city of Dortmund say investigators "are working on the assumption" that the explosions that rocked a professional soccer team's bus were caused by "serious explosive devices." Bongarts/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Dortmund police said the devices that went off near the bus as German team Borussia Dortmund was leaving its hotel for a match Tuesday night "may have been hidden in a hedge near a parking area." AFP/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion The Champions League quarterfinal first leg game between Dortmund and Monaco was called off and rescheduled for Wednesday. AFP/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion The police chief for the German city of Dortmund says it's not clear yet who was behind the explosions that rocked a bus carrying the Borussia Dortmund soccer team and left a player injured. AFP/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion A spokesman at the already crowded stadium informed fans of the cancellation, saying that "there is no reason for panic here at the stadium." AFP/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Bongarts/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion Dortmund Police Chief Gregor Lange told reporters late Tuesday that police decided at an early stage that the soccer team was the target of the explosions and are not excluding any possible angles in their investigation. AFP/Getty Images Borussia Dortmund bus explosion Borussia Dortmund bus explosion A prosecutor says a letter found outside the hotel the team bus was departing from when the explosions happened "takes responsibility for the act." AFP/Getty Images

The local police force - Polizei Nordrhein-Westfalen Dortmund - held a joint late-night press conference along with the football club and the Dortmund public prosecutor.

Police chief Gregor Lange said, in quotes reported by Bild: "This evening at 19:15 there were three explosions in the surroundings of the BVB hotel.

"We must start from (the position this was) a targeted attack on BVB's team."

Dortmund police also revealed a letter had been found, claiming responsibility for the attack.

"The prosecutor's office Dortmund confirms the discovery of a letter near the scene of the crime. The authenticity is currently being tested," the police force posted on Twitter.

The match will now take place at 1745BST on Wednesday, with increased security measures in place.

Monaco fans sing Dortmund songs after hearing of team bus explosion

"The stadium and the surrounding area remain the focal point for police," added Lange.