Stepping up its crackdown on spiralling pro-independence protests by Tibetans, China has arrested over two dozen people and claimed that 170 others had “surrendered” as it rushed more troops to the restive Tibet and nearby provinces where agitators attacked shops and government buildings.For the first time since riots erupted in Lhasa last Friday claiming 13 lives in the worst ever protests against its rule in two decades, China said Tibetan inhabited areas of Sichauan and Gansu provinces were too hit by the unrest.Shops and government offices were attacked in the Aba county on Sunday and a similar scene was replicated in counties of Xiahe, Magu, Lugu and Jone and Hezuo city in the Gannan Tibetan Autonomous Prefecture in southern Gansu.The riots were “closely linked” with Lhasa, Zhang Yusheng, a spokesman with the Gansu provincial government was quoted as saying by official Xinhua news agency last night.Ratttled by the protests, China has ordered its “largest mobilisation” since the unrest began, the BBC reported adding 400 troop carriers and other vehicles were seen on the main road.Two dozen suspects had been arrested in Lhasa for “endangering national security”, looting, arson and “other grave crimes”, the state-run Tibet Daily reported. Tibet regional government said 170 peeple had “surrendered” and most of them have admitted to committing minor offences, Xinhua said. Authorities had asked rioters to surrender by midnight of Monday promising leniency and warning of harsh action against whose who failed to do so. Pamphlets with “Tibetan independence contents” were in circulation in Gannan area on March 10, the day when monks led protests in Lhasa to mark the 49th anniversary of a failed uprising against Chinese rule in Tibet, and the Tibetans in exile in India launched “March to Tibet” to protest the holding of Olympics in Beijing, state media said.Yelling “Tibet independence” and waving the flags of Tibetan government in exile, the protesters stormed into government offices, police stations, hospitals, shops and markets, local government officials said.Lhasa, Gannan and Aba are struggling to recover, officials said.Chinese government updated the toll in the violence saying 325 people were injured in the riots in Lhasa which also caused an economic loss of $28 million.China has said 13 people were killed in the riots but the Tibetan government in exile in Dharamshala in India maintains that 99 people have so far died in clashes with security forces, including 80 in Lhasa.