A day after her two sons were murdered, a 72-year-old woman died of shock in Chhawla area of southwest Delhi, the police said.
Her sons — 49-year-old Suresh Kumar and 32-year-old Satender Kumar — were pulled out of their car by unknown assailants and shot dead at point-blank range on Monday night.
Following the news of their deaths, their mother Maliya Devi had refused to eat anything, the police said.
According to the police, Devi died on Wednesday after seeing her sons' bodies, which were brought home after post-mortem examination.
"She was an old woman and died of natural causes. There is no foul play," said Parmaditya, additional deputy commissioner of police (southwest).
However, the police suspect the role of a neighbour in the brothers' deaths.
They said the brothers, copper traders in Mayapuri, had a property dispute with one of their neighbours. "We have specific information and our teams are conducting raids to arrest the accused," said a senior police officer.
The police said they have taken the statement of the brothers' friend who was with them before they killed.
The assailants had told the friend, Vijender Kumar, to leave because they did not have any enmity with him.
"He has given us vital clues and we are looking into it," said the officer.