Two police officers suffered serious head injuries as they escorted a politician through a throng of activists protesting against a congress held by the far-right Alternative for Germany in the western city of Essen. Unknown assailants kicked the officers in the head after forcing them to the ground, a police statement said. They were taken to hospital. Seven other officers suffered less serious injuries. The assailants were able to escape into the crowd. Activists and police clashed throughout the day. Interior Minister Nancy Faeser condemned the attacks. “We need strong democratic forces and…