FACTBOX: Tibet, Dalai Lama and relations with China

(Reuters) - Chinese officials have declared a "people's war" of security and propaganda against support for the Dalai Lama in Tibet after riots racked the regional capital Lhasa, and some sources claimed the turmoil killed dozens.

The demonstrations, which also spilled into Chinese provinces populated by Tibetans, began early last week after marches around the world to mark the 49th anniversary of a failed uprising against Communist rule.

Following are some facts about Tibet, the Dalai Lama and relations with China:

TIBET:

* Occupying a large, high-altitude and sparsely populated plateau, Tibet is known as the 'roof of the world.'

* The People's Liberation Army marched into the Himalayan region in 1950.

* Wedged between the Himalayan mountain range to the south and the Kunlun range in the north, Tibet borders Myanmar, India, Bhutan and Nepal.

DALAI LAMA:

* The Dalai Lama, Tibet's god-king, fled on horseback after a failed uprising against Chinese rule in 1959 and now lives in exile in northern India. China accuses him of seeking independence for Tibet. The 72-year-old spiritual leader says he only wants greater autonomy for the region.

* Within Tibet, simply having the Dalai Lama's picture can be grounds for imprisonment. Critics say Buddhist monks and nuns loyal to the Dalai Lama have been jailed and tortured.

SOCIAL TENSIONS:

* Activists say tourism and migration by Han Chinese could swamp Tibet's distinctive culture, with ethnic Tibetans receiving less than their share of new jobs and income.

* China's central government has invested billions of dollars in improving Tibet's infrastructure, including a new railway across the snowy plateau that links Beijing and Lhasa.

(Writing by Gill Murdoch, Singapore Editorial Reference Unit; Additional Writing by Paul Grant/Jijo Jacob)