Officials said Mohammed Afzal Guru, who had been on death row since 2002, was executed at Tihar jail near Delhi.

BBC: Afzal Guru: Delhi parliament attack plotter hanged

Earlier this week, Kaur said she had asked the Indian government to take up with Pakistan the question of tightening Singh's security after New Delhi hanged Mohammed Afzal Guru, a Kashmiri man, in February.

NPR: Indians Angry At Convicted Spy's Death In Pakistan

Executions are very rare in India - Afzal Guru's was only the second since 2004, after Mohammed Ajmal Kasab, the sole surviving attacker from the 2008 Mumbai attack was executed in November.

BBC: Afzal Guru: Delhi parliament attack plotter hanged