The German giants confirmed an explosion had happened close to the vehicle, leaving defender Marc Bartra as the only recorded injury. He has been taken to hospital, although his condition is said to not be serious.
German police also confirmed there has been an explosion near the vehicle at around 19h00.
The clash is now set to take place tomorrow evening, at the same venue, with a 18h45 SA local time kick-off.
A tweet from the official Champions League Twitter account read:
The #UCL QF first leg between Dortmund & Monaco has been postponed following a security incident and will be played on Weds at 18.45CEST.
— Champions League (@ChampionsLeague) April 11, 2017