Nearly three dozen Tibetans captured by Chinese troops as they tried to sneak out of their homeland were tortured with cattle prods and forced to do hard labor, a teenager who identified himself as one of the former detainees said, in the first reported account of the fate of the group. Jamyang Samten, 15, said Tuesday that he was one of 75 Tibetans who were making their way over the 5,800-meter-high Nanpa La Pass on September 30 when Chinese border guards opened fire on them, killing a 25-year-old Buddhist nun and another person. The incident was filmed by a mountaineering expedition and broadcast by a Romanian television station, sparking an international outcry. Forty-one of the refugees managed to reach India after the shooting, but 32 others were caught and detained. While Samten said some of those detained have since been released, he is the only member of the group known to have again tried to flee and made it.