TIRUCHY: Thirty-three fishermen, who belong to Tamil Nadu’s Ramanathapuram district, on board four country boats, were detained by the Sri Lankan Navy on Thursday evening, on grounds of trespassing into their territorial waters. Condemning the arrest, SP Rayappan, president, Ramanathapuram District Country Boats Fishermen Welfare Association, sought the intervention of government authorities to help secure the release of those detained fishermen and four boats. Further, he said earlier the fishermen aboard three boats set out to sea off Pamban and another boat off Thangachimadam. They were scheduled to return to shore on Friday after completing their task of multi-day fishing at sea, he said.