From the Mumford & Sons Official Website:
Tuesday, June 12, 2012
With regret, Mumford & Sons have been forced to cancel their upcoming festival appearances in Denmark and Sweden due to a broken hand sustained by Marcus Mumford.
The band were due to perform at Northside Festival in Denmark on Friday 15th June and Hultsfred Festival in Sweden on Saturday 16th June, but the accident, which occurred at the weekend, regrettably means they will no longer be playing.
No other Mumford & Sons shows are expected to be affected.