Metal vets Slayer [ tickets ] have pushed back the start of their "Unholy Alliance" tour due to bassist/vocalist Tom Araya's minor gallbladder surgery, which took place last week.

Only three dates are affected on the tour, which also features Lamb of God [ tickets ], Children of Bodom [ tickets ], Mastodon [ tickets ] and Thine Eyes Bleed [ tickets ]. All three shows have been rescheduled from their original early June dates to new dates at the tail end of the tour.

The touring metal festival, which Slayer [ tickets ] plans to make an annual event, according to an earlier press release, will now kick off June 12 in St. Louis. The seven-week outing—originally slated to both begin and end on the West Coast--will now start in the Midwest.

The rescheduled dates are in San Diego, Las Vegas and Denver. The tour's full itinerary is listed below.

Slayer's four original members--Tom Araya (bass/vocals), Kerry King (guitar), Jeff Hanneman (guitar) and Dave Lombardo (drums)--are at work on their first new album together since 1990's "Seasons in the Abyss." Super-producer Rick Rubin is the project's executive producer, and Josh Abraham (Korn, Velvet Revolver) is producing the set.

The as-yet-untitled disc is expected to surface on Rubin's American Recordings label this fall, but a specific release date hasn't been announced.