Four pupils at a school in the western German city of Wuppertal were injured, at least two of them seriously, in a knife attack on Thursday, according to police and officials. The suspected attacker, who is in custody, is believed to be a 17-year-old male pupil at the school, said Herbert Reul, the interior minister of the state of North Rhine Westphalia, which includes Wuppertal. Two of the victims in the attack are being treated in intensive care for serious injuries, as is the suspected attacker, according to local prosecutors. Multiple knives were used in the attack, prosecutors said. Scho…