With the issue of killing of Tamils in Sri Lanka 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.

He expressed grave concern and unhappiness over the growing casualties among unarmed Tamils as a result of military action, sources said. They 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 assured the Tamil Nadu Chief Minister M Karunanidhi that his government would take all steps to stop the 'genocide' of Tamils in Sri Lanka.

Singh telephoned Karunanidhi to discuss the Sri Lankan issue, a Tamil Nadu government press release said in Chennai.

During the telephonic conversation, Karunanidhi referred to the 'genocide' of Tamils in Sri Lanka and requested the Prime Minister to summon the Sri Lankan High Commissioner in Delhi to convey India's strong protest on the "killings."

He also requested the Prime Minister to take steps for ending the ethnic strife in Sri Lanka and steps to stop atrocities on Indian fishermen,the release said.

The Prime Minister assured Karunanidhi that his government would take all steps to protect Sri Lankan Tamils.

Meanwhile, scores of telegrams were sent by DMK men to the Prime Minister urging him to take steps to stop the "killing of Sri Lankan Tamils by the Sri Lankan Army."

Karunanidhi had on Sunday asked his party men to sent telegrams to the Prime Minister requesting him to take steps to stop the "killings."

Political parties in Tamil Nadu have recently stepped up their campaign on the issue demanding India's intervention to stop the killings of Tamils in Sri Lanka.