The invention provides a method and system for protection in response to a fault in a mixed line. The mixed line comprises two or more sections, with a first substation at a first end and a second substation at a second end. Every two consecutive sections of the mixed line are separated at a junction. The method is performed by an IED, and comprises obtaining one or more measurements of current at the first end, and one or more measurements of current at the second end. The method also comprises identifying a section of the two or more sections having the fault, by estimating a value of current for each junction and comparing the estimated value with the one or more measurements of current. In addition, the method comprises controlling a switching device based on the section identified with the fault.