Chennai: Tamil Nadu chief minister C Joseph Vijay on Monday urged external affairs minister S Jaishankar to intervene immediately to secure the release of 20 fishermen and 270 impounded mechanised boats in Sri Lankan custody.In a letter to Jaishankar, Vijay expressed concern over repeated arrests of TN fishermen by Sri Lankan Navy which have ‘caused fear and distress among fishing communities.’ He referred to the Oct 3 detention of nine fishermen from Rameswaram and seizure of their motorised craft.Traditional fishing in Palk Strait was the primary livelihood of fishermen in Ramanathapuram and adjoining districts, making boat seizures economically devastating for affected families, Vijay said.He urged the Union govt to strengthen India-Sri Lanka Joint Working Group on Fisheries to formulate a constructive, long-term solution. Vijay also asked Jaishankar to take up the matter directly with Colombo to expedite the fishermen’s repatriation and secure the release of all seized vessels.