AT LEAST 19 people were killed and about 20 wounded in a knife attack last night at a facility for the disabled in a city just outside Tokyo in the worst mass killing in generations in Japan.

Police said they responded to a call at about 2.30 am from an employee saying something horrible was happening at the facility in the city of Sagamihara, 50 kilometres west of Tokyo.

A man turned himself in at a police station about two hours later, police in Sagamihara said. He left the knife in his car when he entered the station. He has been arrested on suspicion of attempted murder and trespassing.

Officials in Kanagawa prefecture, which borders Tokyo, identified the suspect as Satoshi Uematsu, and said he had worked at the facility until February. Japanese media reports said he was 26 years old.

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He entered the building about 2.10am by breaking a glass window on the first floor of a residential building at the facility, Shinya Sakuma, head of prefectural health and welfare division, said at a news conference.

Kanagawa Governor Yuji Kuroiwa expressed his condolences to the victims.

The Sagamihara City fire department says that 19 people were confirmed dead in the attack. The fire department said doctors at the scene confirmed the deaths.

The death toll could make this the worst mass killing in Japan in the post-World War II era.

Journalists gather in front of the facility. ASSOCIATED PRESS / AP ASSOCIATED PRESS / AP / AP

A woman who lives across from the facility told Japanese broadcaster NHK that she saw police cars enter the facility around 3.30am.

“I was told by a policeman to stay inside my house, as it could be dangerous,” she said.

Then ambulances began arriving, and blood-covered people were taken away.

Japanese broadcaster NTV reported that Uematsu was upset because he had been fired, but that could not be independently confirmed.

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The facility, called the Tsukui Yamayuri-en, is home to about 150 adult residents who have mental disabilities, Japan’s Kyodo News service said.

Television footage showed a number of ambulances parked outside, with medical and other rescue workers running in and out.

A police officer stand guard at the gate of the Tsukui Yamayuri-en facility Eugene Hoshiko Eugene Hoshiko

Mass killings are relatively rare in Japan, which has extremely strict gun-control laws. In 2008, seven people were killed by a man who slammed a truck into a crowd of people in central Tokyo’s Akihabara electronics district and then stabbed passers-by.

In 2001, a man killed eight children and injured 13 others in a knife attack at an elementary school in the city of Osaka. The incident shocked Japan and led to increased security at schools.

More recently, 14 were injured in 2010 by an unemployed man who stabbed and beat up passengers on two public buses outside a Japanese train station in Ibaraki Prefecture, about 25 miles (40 kilometres) northeast of Tokyo.

A man who lives near the site of the latest attack said he was shocked such an attack happened in the quiet, semi-rural area near Mount Takao, a mountain popular with hikers.

“I never imagined such a horrible thing happening,” Chikara Inabayashi said.

I was astonished, that’s the only thing I can say.

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