(CNN) -- Beijing appears determined to contain the volatile situation in an ethnically Tibetan region of southwestern China by sending in thousands of extra security forces.
The move comes against a backdrop of anger and despair over Chinese rule, culminating in a growing number of protests and clashes with police, as well as a string of acts of self-immolation by Tibetans.
What is the dispute about?
The Dalai Lama is the traditional religious and temporal head of Tibetan Buddhists. He was made head of state at age 15 in 1950, the same year that Chinese troops occupied Tibet, enforcing what Beijing says is a centuries-old claim over the region. The Dalai Lama held negotiations with Chinese officials on Tibetan self-rule with little success. In 1959, he fled Tibet for exile in India after a failed uprising against Beijing's rule left an estimated 85,000 people dead.
Over the years, the Dalai Lama has led calls for self-rule in Tibet, saying China has made life "hell on Earth" for Tibetans since the uprising.
"These 50 years have brought untold suffering and destruction to the land and people of Tibet," he said in 2009 from exile in Dharamsala, India. "Today, the religion, culture, language and identity ... are nearing extinction; in short, the Tibetan people are regarded like criminals deserving to be put to death."
Pro-Tibetan groups such as the International Tibet Network, claim hundreds of thousands of people have died as a result of China's rule, through torture, execution, suicides and starvation.
The groups also claim Tibetans have gradually become the minority population in their own homeland, as Han Chinese -- China's main ethnic group -- have migrated to the region. London-based Free Tibet claims the construction of a rail link to Tibet's capital, Llasa, in 2006 -- part of China's Western Development Strategy (WDS) -- was intended to cement its control over the restive western regions of China, particularly Tibet and Xinjiang, where separatism remained strong.
Why are tensions so high now?
Resentment among Tibetans spilled over in 2008 when a protest in Lhasa turned violent, as Tibetan mobs burned vehicles and shops and attacked ethnic Chinese. Tibetan exiles say more than 200 people died when Chinese security forces clamped down, but Beijing denies this, saying 22 people, mostly Chinese civilians, died during riots. Activists say tensions have remained high ever since.
Last March, a young Tibetan monk died after setting himself on fire in protest against Chinese rule. Phuntsog, a 20-year-old monk from the Kirti monastery in Sichuan province, was the first of 12 protesters -- including the first woman -- to die by self-immolation for the same cause.
Earlier this month, protesters took to the streets in western China to mourn the latest person to die by setting himself ablaze. Citing witnesses, pro-Tibet rights groups said thousands of Tibetans marched on government offices before the police opened fire into the unarmed crowd, killing at least two protesters and injuring dozens.
The Tibetan government-in-exile has called on the international community to take action to halt violence.
"The Central Tibetan Administration urges the international community to not remain passive before the current situation," Lobsang Sangay, the new head of the government-in-exile, said in a statement. "It is high time for it to intervene to prevent further bloodshed."
What does China say?
The reports of the recent protests, which could not be independently verified, contrasted with the account given by Xinhua, the official Chinese news agency. It reported that "dozens of people, including some monks, stormed and smashed some stores along a main street and a police station" in the autonomous Tibetan prefecture of Ganzi in Sichuan.
"The mob, some armed with knives, threw stones at police officers and destroyed two police vehicles and two ambulances," Xinhua reported, saying that the violence left one of the marchers dead and four wounded. Five police officers were also wounded, Xinhua said.
The same Xinhua report went on to accuse the rights groups' accounts as "ill-intentioned hype."
Beijing rejects accusations of oppression of Tibetans, saying its rule has greatly improved living standards for the Tibetan people.
It accuses the Dalai Lama of being a "wolf in monk's clothing" who seeks to destroy the country's sovereignty by pushing for independence. The Dalai Lama maintains that he does not advocate independence but wants genuine autonomy that would allow Tibetans to maintain their cultural, language and religion under China's rule.
China remains unconvinced.
"The Dalai Lama states that he is not seeking Tibetan independence, but Beijing sees this as a mere cover, because he has never openly given up the demand for so-called 'Greater Tibet' autonomy, so Beijing sees his meetings with world leaders as pushing for political goals," Wenran Jiang, political science professor at University of Alberta, told CNN.
Activists say the disturbing acts reflect an increasingly repressive environment under Beijing's control.
Sixteen people, all monks, former monks and nuns, have set themselves alight in the past year. Most of the suicide attempts occurred in Aba Prefecture and the Kirti monastery, also in Sichuan, which has become a focal point for Tibetans angry at the erosion of their culture.
"The incidents are a clear indication of the genuine grievances of the Tibetans and their sense of deep resentment and despair over the prevailing conditions in Tibet," said new Tibetan leader in exile, Lobsang Sangay, in quotes carried by Free Tibet.
"It is therefore of the utmost urgency that every possible effort be made to address the underlying root causes of Tibetan grievances and resentment."
Prominent Tibetan writer and activist Tsering Woeser told CNN last year that this kind of protest will continue as long as the Chinese government's Tibet policy remains the same.
"If there is no improvement Tibetans will feel it's better to die than be alive. They commit suicide to protest," she said.
"The international community should impose pressure and condemn the Chinese government," she added. "But so far, the pressure is not enough, the international community only appeals to Chinese government but there are no real actions such as an economic boycott."
She added that Tibetan Buddhists can't use violence against others to protest, so they harm themselves to get people to pay attention to their plight.
"This is not suicide. This is sacrifice in order to draw the world's attention," she said.
But China has accused "pro-Tibetan independence forces" overseas of encouraging the practice.
"Everyone knows that nowadays, except for the very few evil cults and extremist forces, all religions advocate respect for human life and oppose violence," Ministry of Foreign Affairs spokesperson Hong Lei said in a statement in November.
"It is a challenge to the moral bottom line of all human beings if, instead of condemning the extreme act of self-immolation, some people are hyping or instigating it."
CNN's Jaime FlorCruz contributed to this report.