Gill, the former Director General of Police (DGP) of Punjab who is credited with rooting out militancy in the state, passed away this afternoon at the age of 82.
"KPS Gill will be remembered for his service to our nation in the fields of policing & security. Pained by his demise. My condolences," tweeted Modi who is on a day-long tour of Assam.
An IPS officer, Gill was the chief of Punjab Police from 1988 to 1990 and then again from 1991 until his retirement from service in 1995.
Earlier, a major feather was added to his crown when he commanded 'Operation Black Thunder' in May 1988 to flush out militants hiding in the Golden Temple.
The operation was hugely successful as little damage was caused to the holiest shrine of Sikhs, compared to 'Operation Blue Star' in 1984 carried out by the Army.
In the Operation Black Thunder, around 67 Sikhs surrendered and 43 were killed.