A MAN wielding a knife has killed at least 15 people and possibly injured at least 45 in Japan, reports the Daily Mail.

The man, in his twenties, is believed to be a former member of staff who has turned himself in.

Present indications are that the attacker entered a centre for the disabled in Sagamihara, west of Tokyo, with a knife.

Police were called in around 2:30am local time after residents spotted the attacker. 

Four of those injured are in a serious condition. 

It is believed the attacker went into a centre for disabled people in the city of Sagamihara, west of Tokyo, brandishing a knife.

Police were called to the scene at around 2.30am local time after residents saw a man armed with a knife in the grounds of the Tsukui Yamayuri Garden.

Four of the injured are said to be in a serious condition.