Dortmund squad were traveling to the Signal Iduna Park Stadium for Tuesday's Champions League quarter-final first leg, encountering three explosions damaging the team's bus which led to the postponement of the game and left defender Marc Bartra injured and requiring surgery.
The Dortmund's police chief says they will do "everything humanly possible" to make sure the Champions League match between Dortmund and Monaco takes place safely after the boom attack on the German side.
Both Polizei Nordrhein and Westfalen Dortmund local police force held a joint press conference last night along with the football club and the Dortmund public prosecutor.
The 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 they found a letter claiming responsibility for the incidents.
“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 tonight, with increased security measures in place.
“The stadium and the surrounding area remain the focal point for police,” added Lange.
“We’re preparing a major police presence for tomorrow and will do everything humanly possible to ensure the match can take place safely.”
The police had earlier said in a statement that the explosives “may have been hidden in a hedge near a parking lot”.
Monaco fans that were left facing another night in Germany were offered accommodation by Dortmund fans via the hashtag #bedforawayfans on social media, while the club said on Twitter that all their supporters staying in Dortmund on Tuesday night would be reimbursed up to 80 euros (£68) by the club.
The club also added in a statement: “Faced with this difficult situation, AS Monaco wishes to express its full support to the Borussia Dortmund team and all the components of the club.”
Dortmund goalkeeper, Roman Burki was sitting at the back of the bus alongside Bartra, and told Swiss newspaper website blick.ch how the events happened.
Burki said: “We left the hotel at 7:15pm and went down the street. The bus turned down the main street, and there was a giant explosion.
“I was sitting in the back row next to Marc Bartra, who was hit by fragments of the broken glass.
“After the bang, we all ducked in the bus and those who could threw themselves to the ground. We did not know had happened.
“The police were quick on the scene, and we were safe.
“We’re all shocked – nobody thought of a football match in this moment.”
The Dortmund chief executive, Hans-Joachim Watzke also admitted that the squad were shaken after 26-year-old Bartra, who arrived from Barcelona last summer, had to be taken to hospital for treatment.
He said in a statement: “An explosive strike on the bus was carried out immediately after the departure from the hotel.
“Three explosive devices were placed and triggered on the edge of the road.#
“The whole team is in shock. We have to get through this. It will not be easy for the players. I hope that the team will somehow be able to return to the field.
“Borussia Dortmund is especially strong in extreme situations. Everyone will come even closer together and I’m sure the team will feel this.”
The decision to postpone the match was made after a meeting held at the stadium between European football’s governing body UEFA, representatives of the two clubs and local authorities.
UEFA president Aleksander Ceferin was “deeply disturbed” by the whole events that happened in Dortmund and supported the decision to postponed the match.
He said in a statement: “I was deeply disturbed by the explosions which occurred in Dortmund. The decision taken to postpone the UEFA Champions League match between Borussia Dortmund and AS Monaco was the correct one since we must always prioritise the safety and security of all fans, team officials and players.”
The Dortmund players later returned to their hotel following the incident.