The Sri Lankan navy has arrested three Indian fishermen along with a boat for poaching in the Lankan waters. <br/><br/>Sri Lankan navy said in a statement that the arrests took place south off Mannar last night and 410 mg heroin was found in possession of one of them. It said, the fishermen will be handed over to the Mannar police for further investigation and legal action.<br/><br/>This is the first time in recent times that fishermen have been arrested on drug charges. Fishermen arrested for poaching into Sri Lankan waters are normally released on humanitarian grounds after sometime. The arrests comes days after 16 fishermen along with four boats was arrested.<br/><br/>With the latest arrests, the total number of Indian fishermen in Sri Lankan custody has gone up to 116.