The picture of the knifeman who killed 19 people and injured 25 at a care home for disabled people in Japan has been identified, it has been reported.

Satoshi Uematsu turned himself in following the stabbing spree in Sagamihara, Kanagawa Prefecture - Japan's worst mass killing in decades.

A Twitter account under the Japanese name "Satoshi" was apparently maintained by the 26-year-old, reports Japanese newspaper Asahi Shimbun.

The last tweet was sent about 2:50am (local time) on July 26, shortly after an employee at the Tsukui Yamayurien facility had called the cops.

It states: "May there be peace in the world."

The words "beautiful Japan!!!!!!" were also tweeted in English.

The 7.6 acre facility, established by the local government and nestled on the wooded bank of the Sagami River, cares for people with a wide range of disabilities, NHK said.