Rage Against The Machine triggered angry protests in Minnesota yesterday (September 2nd) when authorities prevented them from playing an impromptu concert.
The band attempted to perform for fans on the State Capitol lawn in St Paul but were told they didn't have a proper permit.
As tensions amongst the crowd escalated, Tom Morello and Zach De La Rocha lead acapella versions of the band's hits 'Bulls on Parade' and 'Testify'.
They then joined a number of the 2000-strong crowd who marched toward the Xcel Energy Centre, which triggered further widescale protests downtown. A number of activists were arrested.
Rage Against The Machine are due to hold a protest concert in the state tonight to coincide with the Republican National Convention.
Last week, the group held a similar event at the Democratic National Convention, which saw Barack Obama accept his nomination as the party's candidate for Presidency.