As Dravida Munnetra Kazhagam continued to mount pressure on the Sri Lanka [Images] Tamil issue, government on Friday summoned Lankan High Commissioner to India C R Jayasinghe and told him that Colombo should address New Delhi's [Images] concerns over the humanitarian situation in the island nation and stop harassing and killing Indian fishermen.

Jayasinghe was called by Foreign Secretary Shivshankar Menon who said Sri Lanka should ensure that the rights of its civilians are respected and they are protected from attacks, sources said.

Menon told Jayasinghe that India was gravely worried over the situation arising out the conflict in Sri Lanka and wanted Colombo to address these concerns, the sources said.

The Foreign Secretary specifically said India wanted Sri Lanka to stop harassing and killing of its fishermen in the common waters between the two countries, they said.

Menon also told the Sri Lankan envoy that Colombo should find a negotiated political solution to the ethnic problem rather than look for a military victory.

The summoning of the Sri Lankan envoy came on a day three more MPs of the government's ally DMK submitted their resignations to their party chief in protest against military offensive in the island nation.

Over the past two days, Prime Minister Manmohan Singh [Images] and External Affairs Minister Pranab Mukherjee have expressed concern over the situation, particularly the 'humanitarian effect' of continuing conflict in Sri Lanka.

The prime minister had on Wednesday said the situation in the island nation is a cause for 'serious concern' and asked Colombo to find a negotiated settlement rather than looking for a 'military victory'.

He said India was concerned over escalating hostilities, losses suffered by civilians and increasing number of displaced persons in Sri Lanka.

Dr Singh said the situation in Sri Lanka calls for a negotiated political settlement which respects the unity and the integrity of Sri Lanka and at the same time respects the essential human rights of minorities, particularly Tamil minorities.

Mukherjee, in a statement on Thursday, expressed worry over the situation and said India will do all 'in its power' to ensure a political settlement to the ethnic problem in the island nation.

"It is essential that their (citizen's) rights be respected, that they be immune from attacks and that food and other essential supplies be allowed to reach them," he said.

Earlier on October 6, National Security Adviser M K Narayanan had summoned Sri Lanka's Deputy High Commissioner G G A D Palithaganegoda and stressed that Colombo should act with 'greater restraint' and address the growing insecurity in the wake of killing of unarmed people there.