ZHONGDIAN, China – China blanketed restive Tibetan areas yesterday with a huge buildup of troops, turning small towns across a wide swath of western China into armed encampments.

Beijing acknowledged that last week’s anti-government protests had spread far beyond Tibet’s borders and that police opened fire on protesters. It warned foreign tourists and journalists to stay away from a huge expanse of territory across four provinces.

In an overture of peace, the Dalai Lama offered to meet with Chinese President Hu Jintao and other leaders, reiterating that he was not asking for Tibetan independence.

China has repeatedly ignored calls for dialogue, accusing the exiled Tibetan leader and his supporters of organizing violence in hopes of sabotaging the upcoming Beijing Olympics and promoting Tibetan independence.

Hundreds of paramilitary troops aboard at least 80 trucks were seen traveling along the main road winding through the mountains into southeastern Tibet. Others set up camp and patrolled streets in riot gear, helmets and rifles in the town of Tiger Leaping Gorge, a tourist attraction in Yunnan province bordering Tibet.

Farther north, the largely Tibetan town of Zhongdian, renamed Shangri-la a decade ago, was swarmed by 400 armed police. Many carried rifles and what appeared to be tear gas launchers. Residents walked freely among the military, and there was no sign of a daytime curfew.

The troop mobilization was helping authorities reassert control after the broadest, most sustained protests by Tibetans against Chinese rule in decades. Demonstrations had flared across Tibetan areas of Sichuan, Gansu and Qinghai provinces in support of protests that started in the Tibetan capital of Lhasa.

Led by Buddhist monks, protests had begun peacefully in Lhasa early last week but erupted into rioting on March 14, drawing a harsh response from Chinese authorities.