A rotor arrangement (RA) for a rotor of a gas turbine, comprising - at least one rotor disk (RD) comprising a plurality of axially extending attachment slots (AS) along its outer periphery (OP) for carrying rotor blades (RB) and a lateral surface (LS) with an annular groove (AG) having an annular opening towards the outward direction, the annular groove (AG) being arranged radial inwardly of the attachments slots (AS) and - a plurality of rotor blades (RB), wherein each rotor blade (RB) comprises an airfoil (AF) and a blade root (BR), each rotor blade (RB) is assembled with its blade root (BR) in one of the plurality of the attachment slots (AS), wherein each of the assembled blade roots (BR) comprises a root extension (RE) with a root groove (RG), said root groove (RG) facing the annular groove (AG) when the rotor blade (RB) is assembled in the attachment slot (AS), and wherein for each assembled rotor blade (RB) a locking element is provided, the locking element engaging the annular groove (AG) of the rotor disk (RD) and the root groove (RG) of the respective rotor blade (RB), 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 (MB) and laterally two tongues (BT), the two tongues are bent and embrace the respective root extension (RE). - at least one rotor disk (RD) comprising a plurality of axially extending attachment slots (AS) along its outer periphery (OP) for carrying rotor blades (RB) and a lateral surface (LS) with an annular groove (AG) having an annular opening towards the outward direction, the annular groove (AG) being arranged radial inwardly of the attachments slots (AS) and a plurality of axially extending attachment slots (AS) along its outer periphery (OP) for carrying rotor blades (RB) and a lateral surface (LS) with an annular groove (AG) having an annular opening towards the outward direction, the annular groove (AG) being arranged radial inwardly of the attachments slots (AS) and - a plurality of rotor blades (RB), wherein each rotor blade (RB) comprises an airfoil (AF) and a blade root (BR), each rotor blade (RB) is assembled with its blade root (BR) in one of the plurality of the attachment slots (AS), wherein each of the assembled blade roots (BR) comprises a root extension (RE) with a root groove (RG), said root groove (RG) facing the annular groove (AG) when the rotor blade (RB) is assembled in the attachment slot (AS), and wherein for each assembled rotor blade (RB) a locking element is provided, the locking element engaging the annular groove (AG) of the rotor disk (RD) and the root groove (RG) of the respective rotor blade (RB), 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 (MB) and laterally two tongues (BT), the two tongues are bent and embrace the respective root extension (RE). wherein each of the assembled blade roots (BR) comprises a root extension (RE) with a root groove (RG), said root groove (RG) facing the annular groove (AG) when the rotor blade (RB) is assembled in the attachment slot (AS), and wherein for each assembled rotor blade (RB) a locking element is provided, the locking element engaging the annular groove (AG) of the rotor disk (RD) and the root groove (RG) of the respective rotor blade (RB), 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 (MB) and laterally two tongues (BT), the two tongues are bent and embrace the respective root extension (RE). <EOS>