A method of selecting between two operation modes in a dual fuel internal combustion engine of the diesel-type, comprising a combustion chamber being at least partly delimited by a piston, a first fuel supply for a first fuel, said first fuel supply being located in or at the combustion chamber and/or in or at an inlet port thereof, and a second fuel supply for a second fuel, - the engine having two different operation modes, both operation modes comprising the steps of: - pre-mixing said first fuel in said combustion chamber and/or In said inlet port, - compressing the charge containing the first fuel to conditions that allow auto-ignition of the second fuel, - performing a first injection of the second fuel into said combustion chamber to initiate auto-ignition of said second fuel, thereby initiating conditions for combustion of the fuel remaining in the combustion chamber after auto-ignition of the second fuel, wherein - said first operation mode is distinguished by homogenous ignition and combustion of the remaining fuel, - said second operation mode is distinguished by pre-mixed flame propagation combustion of the remaining fuel, said method further comprising the step of: - adjusting the amount of the second fuel injected in said first injection of the second fuel, and/or the timing of said first injection of the second fuel, so as to control the combustion chamber temperature and pressure after auto-ignition of the second fuel such that selection between said first and second operation modes is achieved, characterised in that the second operation mode comprises: - pre-mixing said first fuel in said combustion chamber and/or in said inlet port, - compressing the charge containing the first fuel to conditions that allow auto-ignition of the second fuel, - performing said first injection of the second fuel into said combustion chamber to initiate auto-ignition of said second fuel for igniting said first fuel, thereby initiating conditions for pre-mixed flame propagation combustion of said first fuel, and - performing at least one subsequent injection, said subsequent injection supplying additional kinetic energy into the combustion process to thereby enhance turbulence intensity and propagation speed of said flame. - the engine having two different operation modes, both operation modes comprising the steps of: - pre-mixing said first fuel in said combustion chamber and/or In said inlet port, - compressing the charge containing the first fuel to conditions that allow auto-ignition of the second fuel, - performing a first injection of the second fuel into said combustion chamber to initiate auto-ignition of said second fuel, thereby initiating conditions for combustion of the fuel remaining in the combustion chamber after auto-ignition of the second fuel, wherein - said first operation mode is distinguished by homogenous ignition and combustion of the remaining fuel, - said second operation mode is distinguished by pre-mixed flame propagation combustion of the remaining fuel, - pre-mixing said first fuel in said combustion chamber and/or In said inlet port, - compressing the charge containing the first fuel to conditions that allow auto-ignition of the second fuel, - performing a first injection of the second fuel into said combustion chamber to initiate auto-ignition of said second fuel, thereby initiating conditions for combustion of the fuel remaining in the combustion chamber after auto-ignition of the second fuel, wherein - said first operation mode is distinguished by homogenous ignition and combustion of the remaining fuel, - said second operation mode is distinguished by pre-mixed flame propagation combustion of the remaining fuel, - adjusting the amount of the second fuel injected in said first injection of the second fuel, and/or the timing of said first injection of the second fuel, so as to control the combustion chamber temperature and pressure after auto-ignition of the second fuel such that selection between said first and second operation modes is achieved, - pre-mixing said first fuel in said combustion chamber and/or in said inlet port, - compressing the charge containing the first fuel to conditions that allow auto-ignition of the second fuel, - performing said first injection of the second fuel into said combustion chamber to initiate auto-ignition of said second fuel for igniting said first fuel, thereby initiating conditions for pre-mixed flame propagation combustion of said first fuel, and - performing at least one subsequent injection, said subsequent injection supplying additional kinetic energy into the combustion process to thereby enhance turbulence intensity and propagation speed of said flame.