During the Glastonbury performance, which is aired annually on BBC, one of the group’s members, Bobby Vylan, led the crowd to chant, “Death to the IDF,” referring to the Israel Defense Forces, to the shock of organizers and onlookers.

The British punk-rap duo Bob Vylan has been denied entry to the United States after sparking international controversy with a fiery and politically charged performance at the Glastonbury Music Festival on Saturday.

The Glastonbury Festival of Contemporary Performing Arts, to give it its full name, was founded by Michael Eavis in 1970 on his Worthy Farm, 120 miles (some 200 kilometers) southwest of London. It’s still run by the 90-year-old farmer and his daughter, Emily Eavis.