Security forces in northwestern China's Qinghai province attacked and beat a group of elderly Tibetan villagers and women who were blocking construction of a dam last week, injuring an unknown number and later detaining several, according to a local source. The group had sought since the beginning of the year to halt the work near Seching village in the Yadzi (in Chinese, Xunhua) Salar Autonomous County amid concerns it could be linked to mining operations in the area, an area resident told RFA's Tibetan Service on Monday. Chinese police, including about 100 members of a special task force, arrived at the construction site on Aug. 10 to attack the group when younger protesters were away working in the fields, RFA's source said, speaking on condition of anonymity. "They took them away to a secluded place and beat them, and a few were detained," the source said. The beating was reported to be "severe" and several protesters were injured in the assault, but detailed information on the number or names of those hurt was not immediately available. When villagers went next day to county offices to protest, the county chief refused to meet with them, the source said. "Instead, he sent two officials out to rebuke the crowd," he said. Mining operations in Yadzi, including the extraction of copper and gold, may have never been approved by authorities above the county level, the source said, adding that local officials and businessmen are profiting together from the work. Tibet has become an important source of minerals needed for China's economic growth, and Chinese mining operations in Tibet have often led to widespread environmental damage, including the pollution of water sources for both livestock and humans, experts say.