A rotor arrangement for a rotor of a gas turbine, comprising - at least one rotor disk comprising a plurality of axially extending attachment slots along its outer periphery for carrying rotor blades and a lateral surface with an annular groove having an annular opening towards the outward direction, the annular groove being arranged radial inwardly of the attachments slots and - a plurality of rotor blades, wherein each rotor blade comprises an airfoil and a blade root, each rotor blade is assembled with its blade root in one of the plurality of the attachment slots, wherein each of the assembled blade roots comprises a root extension with a root groove, said root groove facing the annular groove when the rotor blade is assembled in the attachment slot, and wherein for each assembled rotor blade a locking element is provided, the locking element engaging the annular groove of the rotor disk and the root groove of the respective rotor blade, characterized in that at least one of the locking elements is, preferably all locking elements are embodied as a locking sheet metal strip (LSMS), which comprises a main body and laterally two tongues, the two tongues are bent and embrace the respective root extension. - at least one rotor disk comprising a plurality of axially extending attachment slots along its outer periphery for carrying rotor blades and a lateral surface with an annular groove having an annular opening towards the outward direction, the annular groove being arranged radial inwardly of the attachments slots and a plurality of axially extending attachment slots along its outer periphery for carrying rotor blades and a lateral surface with an annular groove having an annular opening towards the outward direction, the annular groove being arranged radial inwardly of the attachments slots and - a plurality of rotor blades, wherein each rotor blade comprises an airfoil and a blade root, each rotor blade is assembled with its blade root in one of the plurality of the attachment slots, wherein each of the assembled blade roots comprises a root extension with a root groove, said root groove facing the annular groove when the rotor blade is assembled in the attachment slot, and wherein for each assembled rotor blade a locking element is provided, the locking element engaging the annular groove of the rotor disk and the root groove of the respective rotor blade, characterized in that at least one of the locking elements is, preferably all locking elements are embodied as a locking sheet metal strip (LSMS), which comprises a main body and laterally two tongues, the two tongues are bent and embrace the respective root extension. wherein each of the assembled blade roots comprises a root extension with a root groove, said root groove facing the annular groove when the rotor blade is assembled in the attachment slot, and wherein for each assembled rotor blade a locking element is provided, the locking element engaging the annular groove of the rotor disk and the root groove of the respective rotor blade, characterized in that at least one of the locking elements is, preferably all locking elements are embodied as a locking sheet metal strip (LSMS), which comprises a main body and laterally two tongues, the two tongues are bent and embrace the respective root extension.