IN THIS week's print edition, we look at tense relations between India and Sri Lanka, one element of which is the dispute between south Indian fishermen and the Sri Lankan navy over rights to the narrow Palk Strait, which separates the two countries. One of our correspondents visited fishermen in the south Indian state of Tamil Nadu who were on strike over the clashes.

On March 25th, thousands of men and women went to the train station in Nagapattinam, a quiet coastal town in Tamil Nadu, to hop on to the tracks for a lie-in. Their protest, which involved blocking an 11am express train, was sparked by an alleged knife attack on four local fishermen. The victims say their boat was intercepted by a Sri Lankan naval vessel in the Palk Strait on March 20th. Local newspapers contained photographs of the men bandaged up in an ambulance hours later, although it is still unclear exactly who set upon them.

Attacks on Tamil Nadu's fishermen seem to have become more frequent since the end of Sri Lanka’s civil war in 2009, when Sri Lanka's Sinhalese-dominated government violently quashed a Tamil separatist movement after an intermittent conflict of over 25 years (most of the world's 70m speakers of Tamil are an ethnic group concentrated in Tamil Nadu and northern Sri Lanka). Three of a dozen fishermen interviewed in Akkaraipettai, a village near Nagapattinam, said their boats had been attacked by the Sri Lankan navy or coast guard this year. Sri Lanka’s navy says it directs its officers and sailors not to use force.

Akkaraipettai’s fishermen are no angels in this dispute—as they admit, they often cross the maritime border. Their own polluted and over-fished shores leave them tempted by the fairer waters in Sri Lanka's domain, which have been trawled less heavily due to the recent war. Last month, Sri Lanka detained 35 of Tamil Nadu's fishermen for allegedly crossing the line. The 16 fishermen who were hauled in during the first arrest have already been released. The 19 caught up in the second are expecting to be held in custody until April 11th.

Sri Lanka’s navy is now free to patrol the strait, much of which was once controlled by the separatists. It is also interested in these waters because of the island’s ongoing ethnic tensions, says Madura Rasaratnam at the School of Oriental and African Studies in London. Since the war ended, southern fishermen from Sri Lanka's Sinhalese communityhave started ranging farther north and plying the waters. Sri Lanka’s authorities are keen to protect their livelihoods, Ms Rasaratnam says, if not those of the island’s own beleaguered Tamils.