FACTBOX: Who are the Tibetans, what is Tibet?

March 21 - Tibetans in China's southwestern province of Sichuan said on Friday they believed several people had been killed in anti-Chinese riots there this week, disputing official claims none had died in the restive region.

Here is some background about Tibet and the Tibetan populations living in neighboring Chinese provinces.

TIBETANS:

-- Mostly Buddhist Tibetans have lived on remote, high-altitude plateaus and grasslands by the Himalayas for centuries. Hundreds of thousands still follow a nomadic lifestyle, raising yaks, sheep, goats and horses on grasslands.

-- Generally calling themselves "Bodpa", they speak dialects derived from the written Tibetan language.

-- Tibetans have been formally classed as one of China's 56 ethnic groups since Chinese troops were sent in 1950.

TIBET'S HISTORIC BOUNDARIES:

-- Bordering India, Nepal, Bhutan and Myanmar, Tibet's boundaries have changed over the centuries.

-- Known as the "land of snows" and the "roof of the world", it is ringed by mountains -- the Himalayas to the south and the Kunlun mountains to the north.

TIBET AUTONOMOUS REGION (TAR):

-- In 1965 China established the TAR on the central Tibetan plateau. The area the size of South Africa is the highest region on earth at more than 4,000 meters.

-- The capital Lhasa lies in the southeast. The world's highest mountain, Mount Everest, is on its western border with Nepal.

-- The TAR has province-level status. There are some 2.5 million ethnic Tibetans in the TAR, accounting for 92 percent of the TAR's overall population and about 45 percent of all ethnic Tibetans in China, according to official figures.

-- Sizable Tibetan communities live in the neighboring Chinese provinces of Qinghai, Gansu, Sichuan and Yunnan.

TIBETAN EXILES:

-- Tibet's revered Buddhist leader, the Dalai Lama, has lived in Dharamsala, northeast India, since 1960, after fleeing Lhasa following a failed 1959 uprising against Chinese rule.