More than 3000 fishermen from Thanjavur began an indefinite fast here today, demanding the release of 33 fishermen arrested recently by the Sri Lankan Navy.

The fishermen were arrested near Neduthivu over a period of one week for reportedly crossing the International Maritime boundary Line and fishing in the island nation's waters, officials said.

The fishermen had put out to sea in 201 boats from Ammani Chatttiram and Sethubhavachattiram coastal hamlets, they said.