The Sri Lankan Navy today arrested 48 fishermen from Tamil Nadu after firing in the air, official sources said. 12 mechanised boats of the fishermen were also seized by the navy, Fisheries Assistant Director Shivakumar told PTI here. The fishermen, belonging to Pudukottai and Jagadapattinam districts, were taken to Kangesanthurai by the navy personnel, he said. The navymen allegedly rammed their boats against the mechanised vessels and under its impact four fishermen fell into the sea and were rescued by the naval personnel immediately. Later they fired a couple of shots in the air and asked the fishermen to surrender, which they did. The fishermen were later taken to Kangesanthurai.