Punk veterans NOFX debuted a new protest song during a performance at the Occupy LA base camp in Downtown Los Angeles on Sunday.

Bandmates Fat Mike and Eric Melvin performed Wouldn't It Be Nice If Every Movement Had A Theme Song outside City Hall at what was billed as an eviction party.

The event was staged to celebrate what was supposed to be the final day of the seven-week protest inspired by the Occupy Wall Street movement in New York.

NOFX, who also performed at Occupy San Francisco, also played fan favorites Leaving Jesusland and The Decline.

Police swept through the encampment early on Monday morning in a bid to clear the site.