Nineteen people have been killed in a knife attack at a care home for people with mental disabilities in the Japanese city of Sagamihara.

Police have arrested a local man, named by local media as 26-year-old Satoshi Uematsu, in connection with the attack on the Tsukui Yamayuri-en care centre, located about 50km from Tokyo.

Uematsu reportedly broke a window to gain access to the facilityat around 02:30 local time (17:30 GMT) and began stabbing residents of the care home.

He is reported to be a former employee of the facility, and handed himself in to police saying that he wanted disabled people to “disappear”.

Local police say he had sent a handwritten letter to politicians in February in which he threatened to kill hundreds of disabled people, after which “involuntarily hospitalised” for two weeks before being released.

Broadcaster NTV quoted the letter as saying:

“My goal is a world in which, in cases where it is difficult for the severely disabled to live at home and be socially active, they can be euthanised with the consent of their guardians.”

The incident is the worst mass killing in Japan since the Second World War.