Beastie Boys rapper Mike D's injuries from a recent bicycle accident have sidelined the group's late summer tour with political rockers Rage Against the Machine.

Mike Diamond, 34, was riding home from tour rehearsals Saturday when his bike hit a pothole, triggering a spill that injured the rapper's clavicle, damaging several muscles, tendons and ligaments as well, according to a statement issued Wednesday (July 26) by the band's publicity firm, Nasty Little Man.

"The full extent of [Diamond's] injuries has not yet been determined. However, a specialist has recommended that he refrain from all physical activity for the duration of a two- to three-month rehabilitation regimen or risk permanently losing the use of the injured shoulder," the statement said.

Based on that prognosis, Diamond wouldn't be fully recovered until after the Rhyme and Reason tour's scheduled dates, which run through Sept. 10 in George, Wash. The tour was to kick off Aug. 2 in Toronto. It has not been determined whether the outing will be rescheduled, although a publicist for the Beasties said that is the goal.

"I think that is what is insinuated by the statement," a publicist for the group said. The spokesperson refused to comment further, saying questions about Diamond's condition — he is still awaiting surgery — and information on rescheduled dates, ticket exchanges and refunds will be released by the end of the week.

The Beastie Boys' most recent release, the 1999 anthology Sounds of Science, featured such hits as "Hey Ladies" (RealAudio excerpt) and "Intergalactic" (RealAudio excerpt).

Rage Against the Machine also postponed two planned pre-tour performances at the Fillmore in San Francisco on Thursday and Friday, an Epic Records spokesperson said. The band plans to reschedule the dates, which will be recorded for a live album.