New Delhi: A five-judge Constitution Bench of the Supreme Court on Tuesday slammed Tamil Nadu and Kerala for whipping up sentiments on the Mullaperiyar dam issue and "adding fire to the fuel instead of dousing it" by inciting people.

Urging the two states to observe "sensitiveness and sanity", the Apex Court directed Tamil Nadu to ensure that the water level did not breach the 136 feet level and rejected Kerala's plea for restricting the limit to 120 feet.

The bench comprising justices D K Jain, R M Lodha, Deepak Verma, C K Prasad and A R Dave also asked the Union Government to file its response by Thursday on Tamil Nadu's plea for deployment of the Central Industrial Security Force (CISF) for ensuring safety of the century-old dam.

"Both the parties instead of dousing the fire are adding fuel to it. There has to be sanity and sensitiveness, " the bench observed.

Additional Solicitor General Harin Rawal and senior counsel Ashok Bhan, who initially submitted that Kerala had taken sufficient measures to protect the dam, later agreed to file a reply after seeking necessary instructions from the government.

The bench also castigated Tamil Nadu for misusing the Apex Court's earlier orders and oral observations through huge newspaper advertisements and also declined to entertain its plea for restraining Kerala leaders from making any statements on the dam row.

"How can we stop them with a gag order. Kindly see your prayer. How do we issue such a gag order. If somebody wants to protest he can.

"You are issuing press advertisements. Even our oral observations are being mentioned in the advertisements. It is very unfortunate. You must have had some senior counsel's assistance while issuing the advertisements," the bench remarked.

"Court proceedings should not be used for settling political scores. This is a sacred institution, the sanctity must be maintained.

"The chief executive of the state government makes use of the observation of the court proceedings. It may not be proper when the matter is subjudice," the bench told senior counsel Raju Ramachandran, appearing for Tamil Nadu.

"Though there is nothing substantive involved in the controversy both sides are inciting.

"Ultimately the safety of the people is paramount. We cannot compromise on the safety of people. Even one life is important. Why for that matter even the life of an animal or even the forest is important," the bench observed while asking Tamil Nadu to ensure that the water level did not breach the 136 feet fixed by it in its earlier order.

The Apex Court said Kerala's fears of the dam's collapse from possible quakes cannot be brushed aside lightly.

"It (water level) has exceeded 136 feet. It cannot be without basis. You have to ensure it does not exceed. You are bound by it. You cannot permit it to go beyond 136 feet. Between 26 November and December 5 it has gone up," the bench remarked.

The Apex Court asked Additional Solicitor General Rawal as to why the Centre had not taken any stance on Tamil Nadu's plea for deployment of CISF to protect the dam.

"A letter was written to the Prime Minister on December 4. By this time it must have reached you," the bench observed referring to the correspondence between the state and the Centre on the issue.

Rawal then offered to file a reply, following which the court posted the matter for further hearing to December 15.

The Apex Court also declined to entertain Kerala's application for reducing the water level to 120 feet.

"Had the situation been really that serious and very grave, the committee (empowered) would have submitted a report.

"We will not pass any order. It is entirely left to your wisdom. The relief which you have sought cannot be granted until the committee submits a report," the bench said, upon which senior counsel P P Rao, appearing for Kerala, withdrew the application.

While Kerala wants to demolish the dam located in its Idukki district due to the perceived ecological threat and fears of possible collapse of the dam, Tamil Nadu wants the structure to be protected as it caters to irrigation and drinking water needs of a dozen of its districts.

PM concerned over violence in TN-Kerala border areas on dam

Prime Minister Manmohan Singh on Tuesday told Congress leaders from Tamil Nadu that he was "very much worried" over incidents of violence in border areas in the state and Kerala over the Mullaperiyar Dam issue.

He told a delegation of Congress MPs from the state that leaders and people of both states should remain calm and patient till the issue is resolved in an amicable manner.

The delegation brought to Singh's attention the impression that the Centre was not doing enough to cool the tempers over the issue.

"The Prime Minister told us that he was very much worried over the issue and that he wanted officials of both states to meet first. He also noted that Tamil Nadu boycotted lastweek's meeting and assured us that further steps would be taken," Virudhunagar MP Manicka Tagore said.

When the MPs told Singh about the alleged attack on Tamil Nadu Finance Minister O Pannerselvam and other incidents, the Prime Minister said he was "very much worried" over such incidents and counselled patience till the issue is resolved.

"The Prime Minister told us that he was worried after several incidents on the border between the two states. He said everyone has to remain calm. He said we have to wait for the court verdict too," the MP said.