CHAPARHAR, Afghanistan — There was no military curfew in the villages, but, as a precaution, the farmers still informed the local police outpost that they would be in their fields before dawn, with lanterns and shovels, to channel water to their crops.

In a chaotic war of many players on both sides and with civilians bearing the brunt, the advance notice did not save their lives.

On Saturday morning, an elite unit of the Afghan intelligence agency — possibly accompanied by advisers from the American-led NATO coalition — descended on two villages in Chaparhar district in the eastern province of Nangarhar, killing as many as eight farmers in their fields, local elders said.

“It was 4 a.m. My two brothers were out to channel the water, and we had informed the security post that we would be out watering our plots,” said Mohammed Israr, whose o brothers were killed in Mano, one of the villages attacked. “I was upstream, and the helicopters came and fired at my brothers. They were killed, shovel in hand.”