Injection system for an internal combustion engine, comprising - at least one injector, and comprising - a high-pressure accumulator, which is in a fluid connection both with the at least one injector and, via a high-pressure pump, with a fuel reservoir, wherein - a suction throttle is assigned to the high-pressure pump as a pressure setting element, wherein - the injection system has at least two pressure regulation valves (19, 20), via which the high-pressure accumulator can be brought into a fluid connection with the fuel reservoir, characterised by a control device, which is operatively connected to the suction throttle and to the at least two pressure regulation valves (19, 20), wherein the injection system is configured so as, a) in a normal operation, to regulate a high pressure in the high-pressure accumulator by actuating the suction throttle as a pressure setting element, wherein preferably at least one first pressure regulation valve (19, 20) of the at least two pressure regulation valves (19, 20) being actuated to generate a high-pressure disturbance value; so as, b) in a first mode of a protective operation, to regulate the high pressure in the high-pressure accumulator by actuating the at least one first pressure regulation valve (19, 20) as a pressure setting element; and so as, c) in a second mode of the protective operation, to actuate at least a second pressure regulation valve (20, 19) of the at least two pressure regulation valves (19, 20), which is different from the at least one first pressure regulation valve (19, 20), in addition to the at least one first pressure regulation valve (19, 20), as a pressure setting element to regulate the high pressure in the high-pressure accumulator. - at least one injector, and comprising - a high-pressure accumulator, which is in a fluid connection both with the at least one injector and, via a high-pressure pump, with a fuel reservoir, wherein - a suction throttle is assigned to the high-pressure pump as a pressure setting element, wherein - the injection system has at least two pressure regulation valves (19, 20), via which the high-pressure accumulator can be brought into a fluid connection with the fuel reservoir, characterised by a control device, which is operatively connected to the suction throttle and to the at least two pressure regulation valves (19, 20), wherein the injection system is configured so as, a) in a normal operation, to regulate a high pressure in the high-pressure accumulator by actuating the suction throttle as a pressure setting element, wherein preferably at least one first pressure regulation valve (19, 20) of the at least two pressure regulation valves (19, 20) being actuated to generate a high-pressure disturbance value; so as, b) in a first mode of a protective operation, to regulate the high pressure in the high-pressure accumulator by actuating the at least one first pressure regulation valve (19, 20) as a pressure setting element; and so as, c) in a second mode of the protective operation, to actuate at least a second pressure regulation valve (20, 19) of the at least two pressure regulation valves (19, 20), which is different from the at least one first pressure regulation valve (19, 20), in addition to the at least one first pressure regulation valve (19, 20), as a pressure setting element to regulate the high pressure in the high-pressure accumulator. a) in a normal operation, to regulate a high pressure in the high-pressure accumulator by actuating the suction throttle as a pressure setting element, wherein preferably at least one first pressure regulation valve (19, 20) of the at least two pressure regulation valves (19, 20) being actuated to generate a high-pressure disturbance value; so as, b) in a first mode of a protective operation, to regulate the high pressure in the high-pressure accumulator by actuating the at least one first pressure regulation valve (19, 20) as a pressure setting element; and so as, c) in a second mode of the protective operation, to actuate at least a second pressure regulation valve (20, 19) of the at least two pressure regulation valves (19, 20), which is different from the at least one first pressure regulation valve (19, 20), in addition to the at least one first pressure regulation valve (19, 20), as a pressure setting element to regulate the high pressure in the high-pressure accumulator.