With the issue of killing of Tamils in Sri Lanka [Images] hotting up in Tamil Nadu, India on Monday asked Colombo to act with "greater restraint" and address the growing insecurity in the wake of killing of unarmed people there.

National Security Advisor M K Narayanan summoned Sri Lankan Deputy High Commissioner G G A D Palithaganegoda and conveyed India's concerns over the offensive of the security forces in the Tamil areas and the killing of innocent people there.

Narayanan expressed grave concern and unhappiness over the growing casualties among unarmed Tamils as a result of military action, sources said.

Narayanan said the escalation of military action in the North and the resulting fallout was leading to a great deal of concern in India.

The NSA's move came after Prime Minister Manmohan Singh [Images] assured the Tamil Nadu Chief Minister M Karunanidhi that his government would take all steps to stop the 'genocide' of Tamils in Sri Lanka.