"The Expendables 2" stuntman killed on set in Bulgaria

(CBS/AP) SOFIA, Bulgaria - Tragedy struck the set of "The Expendables 2" when a stuntman died and another was seriously injured while filming an explosion scene on the set of the star-studded action sequel.

Police said Friday that the two men, whose names and nationalities were not disclosed, were performing a stunt involving an explosion on an inflatable boat on the Ognyanovo dam, just outside the capital, Sofia. The incident occurred late Thursday.

The injured man has undergone a five-hour operation and his condition was stable, doctors are quoted by the BTA news agency as saying.

In a statement, the production company Nu Image/Millennium Films confirmed the "unfortunate accident," adding "the filmmakers are working closely with the authorities."

"It is with great regret that we confirm this unfortunate accident," the statement reads. "Our hearts go out to the families and those on the production affected by this tragedy. The filmmakers are working closely with the authorities in responding to and investigating this accident."

The film stars Sylvester Stallone, Bruce Willis, Arnold Schwarzenegger, Jason Statham, Chuck Norris and Jean-Claude Van Damme. It is set to hit theaters on Aug. 17, 2012.

MTV reports that none of the sequel's stars were on set during the accident, because they were filming at a resort more than two hours away.