BEIJING — In a gruesome act of resistance that has played out dozens of times in recent months, six young Tibetans set fire to themselves this week, shouting demands for freedom as they were consumed by flames. On Friday, for the second day in a row, thousands of Tibetan students took to the streets in the northwestern Chinese province of Qinghai denouncing “cultural genocide” and demanding an end to heavy-handed police tactics, exile groups said.

Here in the nation’s capital, where Communist Party power brokers are presenting a new generation of leaders, the outgoing president, Hu Jintao, made no mention on Thursday of the anger consuming China’s discontented borderlands during his sprawling address to the nation.

Asked by foreign reporters about the escalating crisis, delegates to the 18th Party Congress blamed the Dalai Lama, the exiled spiritual leader, or inelegantly dodged the question altogether. “Can I not answer that?” one asked nervously.

But while Tibetan rights advocates have long been inured to impassive officials, they are increasingly troubled by the deafening silence among Chinese intellectuals and the liberal online commentariat, a group usually eager to call out injustice despite the perils of bucking China’s authoritarian strictures.