A diesel engine system and a method for operating said system are provided. The diesel engine system includes a diesel engine provided with an exhaust conduit including a controllable supercharger located upstream of a catalytic converter, a fuel injector located between the supercharger and the catalytic converter, a diesel particulate filter located downstream of the catalytic converter, and a control unit for controlling the engine system. The control unit is arranged to determine that a regeneration of the particulate filter is required, which regeneration is initiated when a predetermined condition is fulfilled. The fuel injector is arranged to inject a predetermined amount of fuel during a first stage of the regeneration, and the supercharger is arranged to vary the flow rate of exhaust during the injection of fuel. The catalytic converter is arranged to combust the injected fuel, and the combusted fuel is arranged to burn particulates trapped within the diesel particulate filter.