India top court commutes 15 death sentences due to delays

India's Supreme Court commuted the sentences of 15 death row convicts on Tuesday, ruling that delays in their execution were grounds to change their sentences to life imprisonment.

"Delay is a grounds for commuting death penalty to life sentence," read a ruling from a three-judge panel headed by Chief Justice Palanisamy Sathasivam, which said mental illness and solitary confinement could also be reasons for commuting sentences.

A total of 15 people had challenged their death sentences due to the time taken for the president to answer their mercy petitions.

They include Devinder Pal Singh Bhullar from northwestern Punjab state, who was convicted over a New Delhi car bombing that killed nine people in 1993.

Indian courts hand down death sentences for the "rarest of rare" crimes. The country had not carried out an execution for eight years until November 2012 when it put to death the only surviving gunman from the 2008 Mumbai attacks.

In February last year, it executed Mohammed Afzal Guru, a Kashmiri separatist convicted of involvement in a deadly 2001 attack on the Indian parliament.

The judgement will affect the more than 400 convicts languishing on death row in India and will place more stringent conditions on the use of the death penalty.