SOUTH PLAINFIELD, N.J. (AP) - Authorities say a fast-burning early morning fire in a duplex home in northern New Jersey killed 5 members of a family and injured four others.

Middlesex County Prosecutor Bruce Kaplan says the cause of the blaze in South Plainfield is not yet known.

Fire officials say the blaze was largely confined to one side of the duplex. That half is completely burned out.

News12 says a relative told the cable TV station the dead include several children.

Neighbor Isabel Scavino says her husband woke up about 3:15 a.m. Thursday to the sound of a screaming child. She tells The Associated Press they heard what sounded like either gunshots or firecrackers.

Scavino says she saw a woman running from the home with several children, and a small child in her arms.