German police are working on the assumption that explosions which rocked the Borussia Dortmund football team's bus were caused by "serious explosive devices".

Police in Dortmund said the devices which went off near the bus as the Bundesliga side were leaving their hotel for a Champions League match "may have been hidden in a hedge near a parking area".

Dortmund defender Marc Bartra suffered injuries to his arm and hand in the incident.

The Champions League quarter-final first leg match between Dortmund and Monaco has been called off and rescheduled for Wednesday.