New Delhi, March 10 : Police in Tibet's capital Lhasa have ramped up security measures ahead of Friday's anniversary of a 1959 uprising against the Chinese, media reported. Beginning February 25, security officials began randomly checking public spaces, guesthouses and hotels, and areas where Tibetan Buddhists perform religious activities and do businesses. Police also have been stopping people to check their cell phones to ensure Tibetans have not been in contact with anyone living outside the region - considered a crime. So far, police have arrested several Tibetans and charged them for alleged political infractions, sources said, RFA reported. On March 1, Lhasa police posted statements on their website about ensuring stability and preventing separatist thoughts and activities. Images on the site showed officers standing at attention and checking car drivers for IDs and books of what appeared to contain lists of people, including thumbnail photographs. Authorities also organised political education campaigns on the policies of the Chinese Communist Party, and appointed local leaders to publicise the nation's law and order, RFA reported. Authorities are taking similar initiatives in other parts of Tibet, including Nagchu, Chamdo, Lhoka and Shigatse. Friday's anniversary commemorates a 1959 revolt in which tens of thousands of Tibetans took to the streets of Lhasa in protest against China's invasion and occupation of their homeland a decade earlier. On March 10 of that year, People's Liberation Army forces violently crackdown on Tibetan protesters surrounding the Dalai Lama's summer palace Norbulingka. Subsequently, the Dalai Lama, the spiritual leader of Tibetan Buddhists, was forced to escape from Tibet seven days later. He fled to Dharamsala, India, followed by some 80,000 Tibetans. A notice they issued earlier said under the current security initiatives about 50,000 individuals and more than 20,000 businesses and the spaces they rent have been searching QR codes, which are widely used in Lhasa for business transactions, RFA reported. /IANS