Sri Lankan navy detained 27 fishermen from southern Indian state Tamil Nadu overnight, accusing them of poaching in the island nation's waters, and released them Thursday morning with a warning.

While 13 fishermen from Jagadapattinam in Thanjavur district were detained along with three boats, 14 fishermen from here were held with their three boats when they were fishing in the mid-sea late last night.

The Lankan navy personnel also damaged their fishing nets, Assistant Director of Fisheries Department Sekar said.

The fishermen, who were taken to Kankesanthurai naval base, were released on Thursday morning after a warning not to fish in the Sri Lankan waters, Sekhar said.

Fishermen from Nagapattinam, Tiruvarur, Karaikal, Thanjavur and Pudukottai had decided to boycott fishing indefinitely from Thursday in protest against the incident.

