A Norwegian teenager detained after the killing of an Ethiopian-origin worker at an Oslo hostel also planned an attack on a mosque, police said on Thursday. The 18-year-old was arrested after the killing on Saturday night of Tamima Nibras Juhar, a 34-year-old social worker, at the Oslo hostel where she was a staff member and the suspect was a resident. The youth is now the subject of a murder and terrorism enquiry after police said he had expressed “opinions hostile to Muslim people”. The suspect “declared that he had the intention of committing an attack against a mosque at Hoenefoss”,...