A private tutor allegedly killed his wife and three minor children in South Delhi's Mehrauli in the early hours of Saturday. The accused has been arrested, police said.

Deputy Commissioner of Police (South) Vijay Kumar said that the accused has been identified as Upendra Shukla. "The incident occurred at around 1 a.m. to 2 a.m. He killed his wife, two daughters and a son with a knife," he said.

Police said that accused's mother lives in the same house and she came to check on the family in the early hours. When Upendra didn't open, she called neighbours who then called the police.

During preliminary investigations, police found a note in which the accused wrote that he has killed his family, but did not mention the reason. He claims he has been depressed, police said.