An electromagnetic inverse scattering procedure for the reconstruction of shallow buried objects in a homogeneous half-space is proposed. The approach is based on the numerical solution of the integral equations that model inverse scattering relationships, and it extends to strong scatterers the imaging capabilities of a previously proposed approach relying on approximated formulations. The inversion is based on the synergic application of a multifocusing strategy based on the iterative multiscaling approach along with an efficient regularization scheme based on the inexact Newton method. Numerical results corroborate the mathematical description to assess capabilities and current limitations of the proposed fully nonlinear technique.