At least 19 people were killed and dozens were wounded in an attack by a knife-wielding man at a facility for the disabled in central Japan early early today in Japan's worst mass killing in decades.

Police in Sagamihara, Kanagawa Prefecture, about 40 km southwest of Tokyo, have arrested Satoshi Uematsu, a 26-year-old former employee at the facility, Japanese media reported.

They said staff called police at 2.30 a.m. local time with reports of a man armed with a knife on the grounds of the Tsukui Yamayuri-En facility.

The 3-hectare 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, Japanese state broadcaster NHK said, quoting an unidentified employee.

Police had recovered a bag with several knives, at least one stained with blood, NHK said. No details were provided about where the bag was found.

The man, wearing a black T-shirt, did not have a knife when he turned himself in at a nearby police station, other reports said. Police said they were still investigating possible motives.

Asahi Shimbun reported that the suspect was quoted by police as saying: "I want to get rid of the disabled from this world."

NHK reported that the facility is usually locked at night but the man broke into the building by smashing a window.

The facility's website said the centre had a maximum capacity of 160 people, including staff.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.