The San Francisco Symphony says a musician's strike is forcing the cancellation of this coming week's East Coast tour.

More than 100 musicians began striking Wednesday after their union and the Symphony failed to reach a new contract agreement.

Executive Director Brent Assink said Sunday that the musicians have rejected a federal mediator's proposed "cooling-off period" that would have allowed them to keep playing concerts. The orchestra will not play in New York's Carnegie Hall, the New Jersey Performing Arts Center in Newark and the Kennedy Center in Washington, D.C.

Violist David Gaudry, chairman of the musician's negotiating committee, could not be reached for comment.

The San Francisco Chronicle says the musicians last went on strike in 1996 to 1997 that led to the cancellation of 43 concerts.