The band was playing at the Gentlemen Of The Road Stopover festival in Walla Walla last week (14-15Aug15), and during the encore, singer Mumford hurled his instrument into the crowd.

The guitar reportedly hit a female gig-goer who was left in need of medical treatment, according to TMZ.com.

The extent of her injuries were not known. Mumford & Sons have yet to respond to the report.