Voicing concern over increased attacks on Indian fishermen by Sri Lankan Navy, Tamil Nadu government on Tuesday asked the Centre to initiate diplomatic steps to check it and urged for withdrawal of the 1974 agreement ceding Katchatheevu islet to the island nation.

Replying to a special call attention on the issue in the assembly, Chief Minister J Jayalalithaa said her government will seek legal course if the UPA government failed to accede to the demand.

The Centre seemed to be of the opinion that fishermen from the state were beyond India, she said while decrying the continued attacks.

In her detailed reply, she said ceding of Katchatheevu had resulted in attacks on Indian fishermen by the Sri Lankan navy as Colombo was not respecting various provisions of the agreement relating to traditional rights.

Citing the Berubari judgement in the Supreme Court in the 1960, she said then West Bengal government had moved the court against ceding it to then East Pakistan and the court had ruled that such ceding could be done only after getting the approval of the two Houses of the Parliament besides constitutional amendments.

"Had (DMK president) M Karunanidhi followed this in 1974 as Chief Minister, Katchatheevu would not have been ceded to Sri Lanka. He failed to do it," she alleged.

Jayalalithaa recalled that in 2008 she had filed a case in the Supreme Court against the 1974 accord with the state Revenue Department later impleading in the case.

She said that every time fishermen were arrested, she took up the matter with the Centre and in the last one month, four attacks had been reported.

"Centre should strongly condemn these attacks, and to end these brutal attacks and arrest of fishermen should take diplomatic steps at least now. The Sri Lankan envoy in Delhi should be summoned and protest should be lodged over the attacks.

"Further, I insist that India should immediately withdraw the Katchatheevu agreement. Else, we will place strong arguments in the Supreme Court when the case comes up", she said.