A former care home worker stabbed 19 patients to death and wounded dozens more before handing himself in at a nearby police station, declaring "I want to get rid of the disabled."

Japan was in shock on Tuesday following the knife attack, which took place at a care home for the disabled in Sagamihara, Kanagawa Prefecture, about 25 miles southwest of Tokyo.

The killer was said to have smashed his way into the facility through a glass window and begun stabbing patients, apparently at random.

Then he walked into a police station, still carrying his blood-stained knives, and told officers: "I did it," Japanese media reported.