Nineteen residents have been killed in a knife attack at a care centre for people with mental disabilities in the Japanese city of Sagamihara. Such attacks are extremely rare in Japan – the incident is the worst mass killing in decades. Police have arrested a man who worked at the centre until February, and who turned himself into police after the attack. He reportedly said he wanted people with disabilities to “disappear”.  The brutal killings have shocked Japan, one of the safest countries in the world.