Some fishermen, who had put to sea from here in 400 boats, were injured after personnel of Sri Lankan navy allegedly hurled stones at them between Arichalmunai and Katchativu on Thursday, officials said.
The Lankan navy personnel also fired in the air several times to scare away the fishermen, fisheries department officials said, adding five fishermen suffered injuries in the head while some others received internal injuries and they had been treated at private hospitals.
The navy man also surrounded the boats of the fisherman and one a boat was damaged in the stone pelting.
The external affairs minister, Mr S.M Krishna, had advised fishermen against straying into Sri Lankan waters, especially in those areas designated as "sensitive" by Lankan government.
He had informed the Rajya Sabha on Wednesday that the number of firing incidents on fishermen in the waters between India and Sri Lanka had come down significantly since the October 2008 bilateral understanding between the countries.