A man is in critical condition in hospital after he allegedly killed his mother, younger sister and left two of his other siblings fighting for their lives in hospital. Police spokesperson Captain Teboho Lephoto said the incident took place in Sebokeng, south of Johannesburg.Lephoto said it is believed that the man attacked his family members with a knife."He stabbed his 43-year-old mother and four-year-old sister to death. The suspect then severely stabbed his 16-year-old brother and nine-year-old sister. The two are in a critical condition in hospital."After attacking his family members, the suspect then allegedly attempted to commit suicide by stabbing himself. He is currently hospitalised under police guard," said Lephoto.The man is expected to face two charges of murder and two of attempted murder.This is a developing story.