Borussia Dortmund defender Marc Bartra was injured and taken to hospital after three explosions went off near the team bus ahead of their Champions League tie with Monaco.
The team tweeted the news after the match was called off because of the explosions as the players were leaving their hotel for the match at 7 p.m. local time (6pm BST).
The team did not provide any details about Bartra's condition, but local reports suggest his injury is not serious.
A spokesman at the already crowded stadium informed fans of the cancellation, saying that "there is no reason for panic here at the stadium."
Dortmund recommended that fans stay in the stadium and remain calm to facilitate an "orderly departure." The club thanked supporters of opponent Monaco for their "patience and understanding" and for chanting "Dortmund! Dortmund!" when the reason for the postponement was announced.
When will the match be played?
Borussia Dortmund have confirmed the match will be played tomorrow, Wednesday 12 April at 5.45pm BST.
The return leg in Monaco will take place next Wednesday, April 18.