Sri Lanka has arrested another 21 Indian fishermen for trespassing, increasing the tension in the narrow channel that separates the countries.
The new arrests came as a Sri Lankan court freed 93 Indian fishermen detained in violent circumstances this week.
Such incidents have been on the rise in the year since a ceasefire has been observed in Sri Lanka's civil war.
The Sri Lankan Navy made the latest arrests.
The fishermen freed by the court in Mannar were in a group of 117 abducted by Sri Lankan fishermen after clashes around Delft Island in the strait.
In those encounters, according to Indian reports, crude weapons were used against the Indian fishermen leaving some seriously injured.
These incidents have become more frequent in the year since the Sri Lankan ceasefire enabled Sri Lankan fishermen to resume fishing off the island's Jaffna peninsula.
Indian fishermen often do not know that they are straying into foreign waters and complain they are being chased away from one small island on which they traditionally had landing rights.
Throughout the 20-year Sri Lankan civil war the Indians have had a difficult time, often detained by the island's navy on suspicion of helping or even being Sri Lankan Tamil Tiger rebels.
Some such clashes were fatal.
Following the ceasefire, the Indian fishermen feel as threatened by their ordinary Sri Lankan counterparts as by the navy.
As one veteran commentator here put it, all the rhetoric of pan-Tamil identity is lost in the din of the Darwinian struggle for survival.