Beijing ? China escalated its rhetoric against supporters of the Dalai Lama on Tuesday, accusing the Nobel Peace laureate’s backers of planning suicide attacks.

The Tibetan government-in-exile dismissed the allegation, saying it remained dedicated to the nonviolent struggle long promoted by their Buddhist leader.

“Tibetan exiles are 100 percent committed to nonviolence. There is no question of suicide attacks. But we fear that Chinese might masquerade as Tibetans and plan such attacks to give bad publicity to Tibetans,” said Samdhong Rinpoche, prime minister of the government in exile in Dharmsala, India.

Public Security Ministry spokesman Wu Heping said searches of monasteries had turned up 176 guns, 13,013 bullets, 19,000 sticks of dynamite, 7,725 pounds of unspecified explosives, two hand grenades and 350 knives.

He provided no details or evidence.

“To our knowledge, the next plan of the Tibetan independence forces is to organize suicide squads to launch violent attacks,” Wu said at a rare news conference on Tuesday.

Beijing has repeatedly lashed out against the Dalai Lama and his supporters since March 14 anti-government riots in Tibet, labeling the spiritual leader a “cat’s paw of international anti-China forces” and denouncing protesting monks as the “scum of Buddhism.”

The U.S. State Department called the Dalai Lama a “man of peace” who wanted only to talk with China about the situation in Tibet.

“We continue to encourage the Chinese to engage in dialogue with the Dalai Lama and his representatives,” State Department spokesman Tom Casey said.

In recent days China has been showing decades-old propaganda films on state television portraying Tibetan society as cruel and primitive before the 1950 invasion by communist troops. China has ignored international calls for mediation and refuses to discuss accusations of discrimination, repression and economic disenfranchisement.

The 72-year-old Peace Prize winner has condemned the violence in Tibet and urged an independent international investigation into the unrest and its underlying causes. The Dalai Lama has repeatedly said he seeks autonomy for Tibet under Chinese rule.

Chinese state media says 18 civilians and one police officer were killed in the Lhasa riots. All but one were migrants from other parts of China, among the many who have flooded into the region in recent decades.

Tibetan exiles say the violence and the harsh crackdown afterward left nearly 140 people dead.