Two fishermen drowned and three others were injured when their boat capsized while being chased allegedly by Sri Lankan naval vessels off Rameswaram.
Thirty others were arrested for reportedly crossing the International Martime Boundary Line, officials said.
The injured fishermen told fisheries department officials on their return that some of their boats were damaged after the naval personnel pelted stones at the vessels and hurled wooden logs. They also cut the fishing nets of all the boats.
The naval personnel arrested 30 fishermen and seized seven boats, they said.