Johannesburg - The case against a man accused of stabbing two toddlers, their mother, and grandmother has been withdrawn, the National Prosecuting Authority (NPA) said on Friday.The 33-year-old man was arrested on Thursday afternoon."The matter is not on the roll," said NPA spokesperson Phindi Louw."It is due to insufficient evidence."The man was scheduled to appear in the Protea Magistrate's Court on Friday but did not do so.Two boys, aged 2 and 3, and their 20-year-old mother were attacked during a robbery in their home in Dobsonville Extension 3 on Tuesday night. Two men were believed to be involved.The 2-year-old boy was stabbed three times on his head, and the 3-year-old stabbed eight times in his body. The boys' mother received multiple stab wounds on her left arm.The boys' 60-year-old grandmother was cut on her forehead during the robbery.The robbers fled the scene with electrical appliances.