Five days before the highly anticipated Rage Against The Machine concert on the Plains of Abraham at the Summer Festival, singer Zack de la Rocha injured his leg on stage on Monday night.

• To read also: FEQ: explosive Halsey on the plains

• To read also: [EN IMAGES] FEQ: Three Days Grace kings and masters at the Parc de la Francophonie

The incident happened during the band's second concert of the tour, at the United Center in Chicago.

According to Consequence of Sound, de la Rocha injured himself after four songs. He left the stage, helped by the other members of RATM, before returning to complete the show, seated on a monitor.

He reportedly attempted to stand up on a few occasions, but was unable to put weight on his leg.

Reached late Monday evening, Summer Festival communications director Samantha McKinley said the organization was aware of the incident and was waiting for more information.