Spoiler: English Borussia Dortmund's team bus was hit by three explosions while on its way to the Champions League semi-final against Monaco on Tuesday evening, leaving one player injured in hospital. German security sources said it was a targeted attack on the team bus, shattering one of the vehicle's windows. Police said "serious explosive devices" were used. A letter found near the site of the attack "takes responsibility for the act", a German prosecutor said. Paid content Recommended by There were reports the devices, which were concealed in a hedge, could have detonated by a mobile phone or a garage door-opening device. A supporter of Borussia Dortmund reacts at the stadium in Dortmund CREDIT: EPA High levels of security were in place across the city on Tuesday night and there will be a large security force presence at Wednesday night's game, police said, adding they did not not want to jump to conclusions that the attack was terror-related. Germany is on high terror alert following a spate of recent attacks, several of which have been claimed by the Islamic State of Iraq and the Levant terror group. Fans of Dortmund are concerned of the bomb attack to the bus of Borussia Dortmund prior to the UEFA Champions League Quarter Final first leg match between Borussia Dortmund and AS Monaco at Signal Iduna Park CREDIT: GETTY Spanish international, Marc Bartra, was undergoing an operation for a broken hand, a club spokesman said. "The bus turned onto the main road, when there was a huge noise - a big explosion," Dortmund's Swiss goalkeeper Roman Burki said. "After the bang, we all crouched down in the bus. Anyone who could, threw himself on the floor. "We did not know if more would come." Burki said Bartra was "hit by splinters of broken glass". In this file photo dated Wednesday, Sept. 14, 2016, Dortmund's Marc Bartra celebrates after scoring during the Champions League Group F soccer match between Legia Warsaw and Dortmund CREDIT: AP The game was postponed to Wednesday evening, with Borussia Dortmund fans offering Monaco supporters accommodation in the city so they can watch the match. Monaco fans had chanted in solidarity with their Dortmund rivals. Hans-Joachim Watzke, Dortmund chief executive, said: "The whole team is in a state of shock, you can't get pictures like that out of your head. "I hope the team will be in a position to be able to compete tomorrow on the pitch. Forensics examines the crime scene next to the team bus of Borussia Dortmund after it was hit by three explosions in Dortmund CREDIT: EPA "In a crisis situation like this, Borussia pulls together." Lukasz Piszczek, a defender for Dortmund, said: "As we were driving alongside a number of cars, a bomb went off at the side of the road. Bartra has cast on his arm. He's in the hospital." The incident sparked memories of the suicide bomb attack at the Stade de France during the Paris attacks of November 2015. 2:58am 'The thoughts of every one of us at Fifa are with the people of Dortmund' “The thoughts of every one of us at FIFA are with the people of Dortmund, and the fans of both Borussia Dortmund and Monaco following today’s troubling events," Gianni Infantino, Fifa's president, said in a statement. "We are closely monitoring the condition of BVB’s Marc Bartra, and wish him a speedy recovery from his injuries. "FIFA condemn the incidents in Dortmund. We are all awaiting further details of the incident." 10:49pm High security levels 'due to risk of terror attack' German police have said there are high levels of security in place due to the risk of a terror attack - but that they do not want to jump to conclusions and say the Dortmund explosions was a terror attack. 10:40pm Letter found near attack site 'takes responsibility for the act' A German prosecutor has said the letter found near the Dortmund team bus "takes responsibility for the act". 10:32pm Bartra being operated on for broken hand The club's centre-back is undergoing an operation for a broken hand, Dortmund's spokesman has said. 10:31pm Letter found near Dortmund bus blast A police press conference is underway. The German state prosecutor has said a letter was found near the site of the blasts and is being examined. 10:02pm 'No evidence of terrorist connection' Police have so far found no evidence of a terrorist connection, the German Press Agency (DPA) is reporting. 10:01pm 'We are all with Borussia Dortmund' Angela Merkel's spokesman, Steffen Seibert, has tweeted: "Tonight we are all with Borussia Dortmund": Follow Steffen Seibert ✔@RegSprecher Gute Besserung, @MarcBartra! Große Reaktion der Monaco-Fans. Heute abend stehen alle zum @BVB. 2:36 AM - 12 Apr 2017 203203 Retweets 874874 likes 9:16pm Footage from the Monaco fans chanting in solidarity with Borussia Dortmund Monaco fans chant in solidarity with Borussia Dortmund 00:27 9:05pm 'Serious explosive devices' used in attack German police have said they working on the assumption "serious explosive devices" were used in the attack on the Dortmund team bus. 8:54pm 'Targeted attack on the Dortmund team bus' Spiegel magazine is reporting that German security sources believe it was a targeted attack on the team bus, writes Justin Huggler in Berlin. The explosives were probably hidden in a hedge by the side of the road. Bartra's injuries are not thought to be serious. Lukasz Piszczek, a defender for Borussia Dortmund, told Poland's Przeglad Sportowy newspaper: "As we were driving alongside a number of cars, a bonb went off at the side of the road. Bartra has a cast on his arm. He's in the hospital." 8:33pm Dortmund making efforts to help Monaco fans make it to the game tomorrow. Follow Borussia Dortmund ✔@BVB Dear supporters of @AS_Monaco_EN! If you need accommodation in Dortmund, please check #bedforawayfans. #bvbasm 2:10 AM - 12 Apr 2017 26,78726,787 Retweets 41,24341,243 likes 8:07pm The damaged team bus The Borussia Dortmund team bus is seen after an explosion near their hotel before the game CREDIT: REUTERS Players after the incident: Head coach Thomas Tuchel, right, and players of Borussia Dortmund stand outside their team bus after it was damaged in an explosion before the Champions League quarterfinal CREDIT: AP 8:02pm 'The whole team is in shock' Hans-Joachim Watzke, the Borussia Dortmund CEO, has said: "The whole team is in a shock. You will not get those pictures out of your head. I hope that the team is able to compete on the field." 7:58pm The stadium announcement The scoreboard announces the postponment of the game prior to the UEFA Champions League Quarter Final first leg match between Borussia Dortmund and AS Monaco at Signal Iduna Park CREDIT: GETTY 7:53pm Police secure Borussia Dortmund hotel Police near the Borussia Dortmund team hotel after the explosion CREDIT: REUTERS 7:48pm Who is Marc Bartra, the player injured in the team bus explosion? Bartra, 26, joined the German club last summer from Barcelona, where the Catalan had graduated from the famed La Masia academy. The centre-back has represented Spain 13 times since his international breakthrough in 2013, and has also played five non-competitive matches for Catalonia. Dortmund's Spanish defender Marc Bartra (L) and Bayern Munich's Polish forward Robert Lewandowski vie for the ball during the German first division Bundesliga football match FC Bayern Munich v BVB Borussia Dortmund in Munich, southern Germany, on April 8, 2017 CREDIT: AFP Bartra has been a regular feature for Dortmund in his first season with the club, making 18 league appearances and seven more in the Champions League, scoring one goal and making three assists along the way. Read our full profile of the player. 7:45pm 'Bartra sustained hand injury in blasts' Follow Derek Rae ✔@RaeComm Hans-Joachim Watzke has confirmed over pa, hand injury suffered by Bartra. 1:43 AM - 12 Apr 2017 1313 Retweets 1010 likes 7:44pm 'No threat to anyone inside the stadium' Follow Derek Rae ✔@RaeComm Dortmund police have just tweeted saying there is no reason to think there is a threat to anyone in the stadium. 1:41 AM - 12 Apr 2017 2626 Retweets 3030 likes 7:44pm Barcelona express concern for their former player, Marc Bartra Follow FC Barcelona ✔@FCBarcelona All of our support to @MarcBartra, @BVB and their fans 1:28 AM - 12 Apr 2017 6,7216,721 Retweets 9,8779,877 likes 7:43pm Solidarity shown by the Monaco fans in the stadium View image on Twitter Follow Borussia Dortmund ✔@BVB Thanks for your patience and understanding and the "Dortmund! Dortmund" chants, dear supporters of @AS_Monaco_EN! 1:38 AM - 12 Apr 2017 12,54912,549 Retweets 22,46822,468 likes 7:42pm First images of the team bus Follow Dortmund English @DortmundEN Pictures of the Dortmund bus following the explosion. 1:39 AM - 12 Apr 2017 8282 Retweets 4141 likes 7:34pm Match postponed Officials confirm the Champions League quarter final has been postponed to Wednesday. Message displayed on the big screen within the ground reads ' BVB of Twitter: Bei Abfahrt unseres Busses hat sich ein Vorfall ereignet. Eine Person wurde dabei verletzt. Weitere infos folgen.' 'BVB on Twitter: When we left our bus, an incident occurred. One person was injured. More information will follow CREDIT: EMPICS SPORT 7:30pm Three explosions went off near team bus Police have said that three explosions went off near the team bus as it approached the stadium in Dortmund. 7:29pm Marc Bartra named as injured Borussia Dortmund player The Spanish centre-back has been named as the injured player. A file picture dated 06 December 2016 of Borussia Dortmund's Spanish defender Marc Bartra CREDIT: EPA 7:28pm Decision on whether match will be abandoned at 19:30 BST Fans are awaiting the verdict in the stadium. 7:22pm 'Windows broken' during explosion Windows were broken during the explosion, according to a statement from Dortmund police. The bomb went off as the bus passed a junction at Schirrmannweg and Wittbraucker Strasse, which is near the L'Arrivée hotel and spa. 7:08pm Borussia Dortmund tells fans - stay calm The club has asked those in the stadium to remain calm as it investigates, adding that emergency workers were at the scene. "We will inform you as soon as there is news," the club added in a tweet. Follow Borussia Dortmund ✔@BVB Bitte bewahrt Ruhe. Derzeit tagt der Krisenstab im Stadion. Wir informieren umgehend, sobald es Neuigkeiten gibt. 1:06 AM - 12 Apr 2017 2,9842,984 Retweets 3,6263,626 likes 7:03pm More on the reported explosion Follow Borussia Dortmund ✔@BVB Bombenexplosion am Mannschaftsbus am Mannschaftshotel. Spieler in Sicherheit. Keine Gefahr im und am Stadion. Weitere Infos folgen. #bvbasm 1:01 AM - 12 Apr 2017 14,32214,322 Retweets 7,9497,949 likes 6:59pm Reports that one person has been injured Follow Borussia Dortmund ✔@BVB Bei Abfahrt unseres Busses hat sich ein Vorfall ereignet. Eine Person wurde dabei verletzt. Weitere Infos folgen. #bvbasm 12:40 AM - 12 Apr 2017 4,8144,814 Retweets 3,1963,196 likes 6:57pm This from German newspaper Bild Although we cannot confirm whether the explosion was ON the bus or NEAR the bus. Follow David Jordan @DavidJordanTS Explosion on Dortmund bus, one player injured http://www.bild.de/sport/fussball/champions-league/explosion-am-mannschaftsbus-von-borussia-dortmund-51257066.bild.html?wtmc=twttr.shr … 12:56 AM - 12 Apr 2017 Auf dem Weg ins Stadion - Scheiben kaputt! Explosion am Dortmund-Bus Vor dem Champions-League-Spiel gegen Monaco soll es am Mannschaftsbus von Borussia Dortmund eine Explosion gegeben haben. bild.de 1717 Retweets 22 likes 6:55pm 'Explosions' near Borussia Dortmund team bus Reports are coming in that there has been an explosion near the Dortmund team bus. More as soon as we have it. Ba vụ nổ vừa xảy ra nhằm vào xe buýt chở CLB Borussia Dortmund đến trận bán kết CL. Vụ nổ khiến một cầu thủ bị thương và nhập viện. http://www.telegraph.co.uk/football...s-monaco-champions-league-live-score-updates/