An arrangement for attenuating vibrations of blades attached to a peripheral surface of a rotor of an axial turbine. A through hole is formed in each rotor blade in a generally thickness direction of the blade so that the through holes in combination define a single annular passage near a rotor surface when all of the rotor blades are attached to the rotor. A wire is provided to extend through the aligned through holes. Thus, the wire frictionally contacts the through holes when the blades are caused to vibrate due to a gas pressure and a centrifugal force generated upon operation of the axial turbine. Friction contact between the wire and the through holes attenuates vibrations of the blades.