Officials said that the incident occurred on Monday when the three fishermen, Rajkiran (30), Suganthan (23), Arockia Xavier (32) ventured into the sea near the International Maritime Boundary Line (IMBL) at Katchatheevu.
Spotting the Sri Lankan naval vessel, the fishermen tried to escape. However, two fishermen were detained by the Sri Lankan Navy while Rajkiran fell into the sea.
A statement from the Sri Lankan Navy said that it has "rescued" two Indian fishermen from a sinking vessel while they were "poaching" in Sri Lankan waters, but a third fisherman had gone missing following the incident and the Navy is searching for him.
The statement said that the Navy was engaged in "chasing away" Indian trawlers, and one vessel with "aggressive manoeuvres" resisted the chase which resulted in a collision with the naval vessel.
The statement added that the two "rescued" fishermen were in naval custody and were detained in Kankesanthurai in Jaffna.
Tensions between Indian and Sri Lankan fishermen and Indian fishermen and the Sri Lankan Navy have been on the rise for the past one year in the Palk Straits.
Northern Sri Lankan fishermen had complained against Indian fishermen "poaching" in Sri Lankan waters and had written a letter to the Indian government to take immediate action against those venturing into Sri Lankan waters crossing the IMBL.
Earlier, in January, four fishermen from Tamil Nadu, Samson Darwin (28), A. Mesiya (30), V. Nagaraj (52) and S. Senthilkumar (32), who had set sail from Pudukottai on January 18, 2021, died allegedly after their boat sank when the Sri Lankan Navy tried to arrest them.
Fishermen of the hamlet alleged that they were beaten to death by the Sri Lankan Navy for crossing the IMBL.
The then AIADMK government had announced a compensation of Rs 10 lakh to the families of each of the fishermen who died.