We prove the strong unique continuation property for manybody Pauli operators with external potentials, interaction potentials and magnetic fields in L p loc (R d ), and with magnetic potentials in L q loc (R d ), where p > max(2d/3, 2) and q > 2d. For this purpose, we prove a singular Carleman estimate involving fractional Laplacian operators. Consequently, we obtain the Hohenberg-Kohn theorem for the Maxwell-Schrödinger model.