Returning to this Indian fishing village, Sakthivel quickly sold his boat and swore off fishing. He told friends that he was too frightened to return to the sea. But, uneducated and jobless, he knew only fishing. Then his first child was born. So he borrowed money, bought a new boat and again set out toward Sri Lanka, and never returned. He has been missing for almost a year.

"Now my husband is gone," said his wife, Maheshwari, 21, who like most people in this village uses a single name. "How can I manage?"

At the bottom of the Indian subcontinent, a fishing war is straining relations between India and Sri Lanka as Indian fishermen, often poor and desperate, regularly cross into Sri Lankan waters and run afoul of the Sri Lankan Navy. Figures differ, but according to one report at least 100 Indian fishermen have been killed and 350 seriously injured in recent years — another example of the volatility of maritime issues in Asia.

The dispute is rooted in a complicated blend of local factors: the steady depletion of fish stocks, partly because of overfishing by Indian trawlers; the aftermath of the 2004 tsunami, which saw relief funds partly used to expand the Indian fishing fleet even as fish populations declined; and the end of the long Sri Lankan civil war in 2009, which has meant the return of the nation's fishing boats to waters once plied almost exclusively by Indians.

The dispute is intensified by history and proximity. At the closest point, the two countries are separated by barely 10 nautical miles, even as both sides are bound by ethnicity. Tamils dominate India's southern state of Tamil Nadu and have close cultural ties to Tamils in Sri Lanka, even providing support to Tamil rebels or accepting refugees during the fighting that ended with a government victory.

The postwar tensions remain in Tamil Nadu. The state's chief minister, Jayalalithaa, recently called on India's military to stop joint exercises with the Sri Lankan military. This week, she suspended a bureaucrat who allowed a Sri Lankan school to play a soccer match in the state, and on Monday protesters confronted pilgrims from Sri Lanka who had come to Tamil Nadu for a religious event.

Here in Vellapallam, the fishing dispute is deeply personal, since fishing is practically the only livelihood available. When the village was devastated by the 2004 tsunami, relief money was used to build concrete houses for families or to help finance new fishing boats. Nearly all of the village fishermen use small, motorized boats rather than the big trawlers docked at other nearby towns. For many years, fishermen say, they stayed close to the Indian coast, but they have gradually pushed farther out to sea as fish populations have declined.

As they have gotten closer to Sri Lankan waters, or crossed into them, fishermen say, the Sri Lankan Navy is often waiting. One fisherman, a wiry, wet-eyed man named Pakkirisamy, pulled off his shirt to show bruises and welts on his back. He said Sri Lankan naval officers beat him last month with steel rods and heavy ropes. He said they dumped his fuel in the sea and ordered him to return to India. He rigged a sail and arrived eight hours later.

It is a common story. Other fishermen described their equipment being confiscated, their cellphones stolen and their iceboxes of fish seized. Several described being attacked by Sri Lankan sailors even as a bilateral agreement between the two countries prohibits such treatment. Once, they said, Sri Lankan naval ships only harassed the bigger trawlers, but now they were going after small boats, too.

"This is risky work," said a fisherman named Dhanabal. "But we don't have any other skills. We are illiterate. We are poor."