A family of four and their security guard were found dead with stab wounds at their house in Shahdara’s Mansarovar Park locality in East Delhi on Saturday morning, the Hindustan Times reported.

Shahdara Deputy Commissioner of Police Nupur Prasad said the victims were 86-year-old Urmila, her three daughters Sangeeta, Nupur and Anjali, and security guard Rakesh.

“Urmila’s husband had died a few years ago and she lived with her three daughters,” Prasad said. The family rented out properties they owned to seven other families.

The police said they had not found any signs of forced entry, leading them to believe that the murderer was known to them, The Hindu reported. Several teams have been formed to identify the suspects, but the police have not made any progress yet. Investigators are trying to ascertain whether a property dispute was behind the murders.

The bodies of the victims have been sent for an autopsy.