Police escort Dortmund's players after the team bus of Borussia Dortmund had some windows broken by an explosion some 10km away from the stadium prior to the UEFA Champions League 1st leg quarter-final football match BVB Borussia Dortmund v Monaco in Dortmund, western Germany. Photo/AFP

Berlin: A bomb explosion hit the bus carrying German football team Borussia Dortmund to a Champions League match on Tuesday, the club said in a tweet. Dortmund defender and Spain international Marc Bartra was injured and in hospital, Xinhua news agency reported.