Updated

A player for one of Germany's top soccer clubs was injured Tuesday after three explosions went off near the team bus as it set off for a Champions League quarterfinal match, police said.

Borussia Dortmund's defender Marc Bartra was injured in the incident, the team said, adding that Bartra was "in safety" and that "there is no danger in and around the stadium."

The chief executive of the team said Bartra was injured on the arm and hand when three explosions went off near the team bus.

Dortmund Chief Executive Hans-Joachim Watzke said the injuries to the Spanish defender Tuesday night are "nothing life-threatening."

It was unclear what caused the explosions ahead of the first leg match between Borussia Dortmund and Monaco, which was later called off and rescheduled for Wednesday.

The police chief for Dortmund, Gregor Lange, said it's not clear yet who was behind the explosions, but police decided at an early stage that the soccer team was the target of the explosions and are not excluding any possible angles in their investigation. Police said the explosions took place in the run-up to the match at around 7 p.m. local time.

Prosecutor Sandra Luecke said at a news conference a letter found outside the hotel the team bus was departing from when the explosions happened "takes responsibility for the act."

Luecke added that authorities won't give details of the letter at this stage, citing the ongoing investigation.

Dortmund police said the devices that went off near the bus as German team Borussia Dortmund was leaving its hotel for a match Tuesday night "may have been hidden in a hedge near a parking area."

"The team is totally shocked, that's clear. It's our task now to digest this somehow because it's only 24 hours before we have to play. That's our job," Watzke said.

He added that there was "no alternative" to rescheduling the match for Wednesday, as Monaco also has to play at the weekend and the return Champions League match is scheduled for next week.

"It's a very unfortunate situation but there was no other way," he said.

Dortmund is located in western Germany, in the densely populated Ruhr industrial region.

This is the second time in recent times that a soccer match in Germany has been postponed over security concerns.

In Hannover, in November 2015, Germany's international soccer friendly against the Netherlands was canceled just before kickoff after police feared an explosive device might be detonated at the stadium.

It came days after devices were detonated outside the Stade de France in Paris as France was playing Germany as part of a coordinated attack on the French capital.

The Associated Press contributed to this report.