The Mars Volta spectacularly walked off at US festival Endfest on August 12 after being pelted with bottles of urine and suffering technical problems.
Guitarist Omar Rodriguez-Lopez smashed his guitar twice against his amp and then threw it to the ground, before leaving the stage in protest at the problems.
Cedric Bixler-Zavala told the crowd: “I will pay $100 to $1,000 to somebody to find the person that’s throwing urine up here. I will give you free merchandise and a lifetime supply [of tickets] to a Mars Volta show.
“Find that person and kick his ass for me, bring me his head – and we’ll be friends.”
Bixler-Zavala also jokingly attributed the technical problems to the festival’s site, saying: “That’s what happens when you decide to build a venue on a sacred burial ground.”
Before walking off, the ex-At The Drive-In prog-rockers had performed ‘Roulette Dares’, ‘The Widow’ and new single ‘Viscera Eyes’.
They had just begun new track ‘Day Of The Baphomets’ when the incidents occurred.
The band has subsequently remained silent over the incident, although the offending audience members were apparently apprehended by security shortly after the band left the stage.
The events are available to watch here on YouTube.