According to official sources, eight fishermen of Perumalpettai in the district ventured into the sea yesterday in two boats from Vedaranyam.
When they were fishing a few knots off-Kodiakarai coast today morning, the Lankan fishermen arrived there in several boats and attacked them with sickles and stones.
Five Indian fishermen received severe injuries in the incident, the sources said.
Other fishermen fishing in the vicinity brought the injured to Nagapattinam shore. They were admitted to government hospital, the sources said.