Sons gunned down their mother and stepfather over a property dispute at Atari village in the jurisdiction of Nishtar Colony police station in Lahore on Thursday, reported 24NewsHD TV channel.
One of their own brothers, who was also injured in the incident, was rushed to the General Hospital for treatment.
According to police, Iftikhar Ali and Razia Bibi had a property dispute with their sons.
After having learned about the incident, SSP investigation reached the site of the incident along with a heavy contingent of police as well as forensic experts, while the Inspector General of Police (IGP) Punjab Rao Sardar Ali Khan and CCPO have given instructions for the arrest of the killer sons as early as possible.
The police later shifted the bodies to a morgue.