Three persons,including two senior citizens from a family all set for Diwali celebration,were killed when unidentified persons attacked them at their residence in Mangrun village of Junnar taluka on Thursday late evening. The deceased have been identified as Dnyandev Kasal (57),his father Harku (75) and Subhadrabai (70). Dnyandev was principal of Sardar Patel High School in the village,police said. According to the police,a gang of armed persons entered the Kasal residence and launched an attack on the family sometime after 10.30 pm on Thursday. The attack was so severe that three from the family died while two others including Dnyandevs son Mayur (24) and wife Pradnya alias Mandabai (45) received major injuries. The incident came to light on Friday morning as some local villagers spotted the family in a pool of blood at their residence. Villagers called the Pune rural police and rushed the injured Mayur and Pradnya to hospital. District Superintendent of Pratap Dighavkar and other senior officers visited the spot for investigation. Police said that some valuables have been looted from the house. But the cost of the valuables looted was not confirmed. The Narayangaon police and local crime branch has initiated investigation into the case. The dog squad was called at the crime scene for investigation purpose. So far the police have no clues about the gangs. Police also suspect that someone having rivalry with the Kasal family may have executed the attack. Police said that Dnyandev was known to be a student-friendly school principal. His wife Pradnya was also teacher at a Zilla Parishad primary school. The incident sent shockwaves across the Mangrul village. Local residents said that couple was peace loving and never had any quarrels with anybody.