It has become routine to strengthen work to maintain stability in March, but the situation is particularly tense this year, Xu said, referring to the anniversary of the deadly riots in the region on March 14, 2008.
Unrest broke out in the regional capital Lhasa and later spilled into other Tibetan regions, leaving 19 people dead and many businesses, houses, and vehicles damaged or looted.
Xiong Kunxin, a professor with the Minzu University of China, said the further tightening could be related to a string of recent self-immolations in Tibetan areas of the provinces of Sichuan and Qinghai bordering Tibet.
"There are five regions that are inhabited by Tibetan people in China. Turbulence in one area can affect others," said Xiong, referring to Qinghai, Gansu, Sichuan and Yunnan provinces where Tibetan communities are located as well as Tibet itself.
A Tibetan, said to be a monk, set himself on fire in Aba Tibetan-Qiang Autonomous Prefecture in Sichuan on Wednesday, the BBC reported. The man was allegedly taken away by police and his current condition is unknown.
Wang Zhongchen, a publicity official with the Sichuan provincial government, told the Global Times Thursday that he was not aware of such an incident taking place.
At least two mob attacks on police stations were reported late January in Tibetan areas of Sichuan, leaving at least two people dead and more than a dozen injured.
An official surnamed Gou with the publicity department of Ganzi in Sichuan told the Global Times that such cases were isolated and that the majority of Tibetan people in the prefecture yearn for stability.
"Such tragic incidents in Sichuan's Tibetan area have to do with geographic and historical factors, which made Tibetan people there more aggressive," Xiong explained. "Meanwhile, less strict management in this area also led to this problem."