Yes, an electromagnetic wave can be produced from a magnetic field, and vice versa, according to Maxwell's equations and the theory of electromagnetism.
Maxwell's equations describe the behavior of electric and magnetic fields and their interrelation in the presence of charges and currents. These equations demonstrate that changing electric fields produce magnetic fields, and changing magnetic fields produce electric fields.
When an electric field changes with time, it generates a magnetic field perpendicular to it. This varying magnetic field then induces an electric field perpendicular to both the magnetic field and the direction of change. This process continues, with the changing electric and magnetic fields mutually inducing each other, creating a propagating wave of electromagnetic energy. This wave is what we commonly refer to as an electromagnetic wave.
So, in summary, a changing electric field creates a magnetic field, which in turn creates a changing electric field, leading to the propagation of an electromagnetic wave. This process can occur continuously, resulting in the transmission of energy through space as an electromagnetic wave.