Police yesterday shot and killed a 24-year-old man they said went on a stabbing rampage that injured several relatives, including his 18-month-old nephew.

Police initially responded to a first floor apartment on East 137th Street in the South Bronx at about 4:45 p.m. after several 911 calls were placed reporting an assault.

Police from the department’s housing bureau were first to respond, and they confronted Michael Harris, whom police said was armed with a knife.

Last night, police said an investigation would disclose what led police to shoot Harris, who was said to have attacked his nephew, sister, mother, and the father of his nephew inside the Bronx apartment before police stopped him.

According to police, the child suffered chin lacerations. The child’s 20-year-old mother – who is Harris’s sister – as well as the baby’s 23-year-old father, were both stabbed in the hands and face. Harris’s mother, 49, experienced a head injury that police attributed to blunt force trauma.

All four were taken to Lincoln Hospital, where they were listed in stable condition. As of last night, police said investigators don’t know what sparked the incident. Detectives also retrieved a knife, box cutters, and a hammer at the scene, police said.

Harris was previously arrested in March 2005 on drug charges.