“THEY are suffering. They have no rights”, says a red-robed monk of his fellow Tibetan Buddhists on the other side of a snow-topped mountain in Sichuan province, in south-west China. His small monastery in Songpan county has so far been spared the worst of an intense security clampdown in Tibetan areas of Sichuan, following a series of self-immolations by Tibetan protesters, most of them monks and nuns. China calls them terrorists, and fears the suicides could spark renewed unrest across the vast plateau.

Over three years ago Tibet and Tibetan-inhabited parts of Sichuan, Qinghai, Gansu and Yunnan were engulfed by the biggest wave of anti-Chinese unrest in decades. Today it is in Sichuan's highlands that the authorities appear to be struggling most to contain simmering discontent among ethnic Tibetans. Sichuan's two “autonomous prefectures” with large Tibetan populations are Aba (Ngawa in Tibetan) and Ganzi (Kardze), whose combined area is almost the size of Great Britain. Much of the area was once part of the famously warlike traditional Tibetan region of Kham. In 1991, China's then Communist Party chief, Jiang Zemin, said that “to keep Tibet stable, it is first necessary to pacify Kham”. That attitude is an ancient one among China's rulers, and still applies.

Songpan county is perched on the north-eastern edge of Aba and has become a magnet for ethnic Han tourists from across China. But tourists are not encouraged to go deep into Aba, where police swarm in remote towns and keep restive monasteries under guard. In Aba town itself, about 150km (95 miles) away, armoured personnel carriers have been deployed on the streets. The authorities have been trying to keep foreign journalists out of the worst-affected areas of Aba and Ganzi. They are nervous that news of the immolations and the grievances that led to them will inflame tensions among more than 1m Tibetans in the two prefectures. (The population in Tibet proper is three times larger.) The handful of journalists who have ventured beyond Songpan this year have been briskly caught and turned back. The police have recently been helped by snowfall on the mountain road from Songpan to Aba town, which is at around 3,200 metres (10,500 feet) above sea level. Officials have reason to be fearful. For Tibetans, self-immolation is a new form of protest. Such acts are difficult for the authorities to prevent, and images of them can have a powerful psychological effect among sympathisers. Eleven Tibetans have tried to kill themselves this way since March. Six have succeeded, the latest a 35-year-old nun in Ganzi on November 3rd. On October 19th Tibet's exiled spiritual leader, the Dalai Lama, held a prayer ceremony for the dead in Dharamsala, the Indian town where he now lives in exile. China's foreign ministry accused him of inciting “terrorism in disguise”. Fire extinguishers have become the accoutrement of choice for police patrols (see picture) as far away as Lhasa, the Tibetan capital some 1,200km south-west of Songpan.

The anger and desperation that has prompted Tibetans to set fire to themselves is common across the plateau. In all of China's Tibetan-inhabited areas, the authorities have rounded up innumerable monks, nuns and laypeople for taking part in the 2008 unrest. Reports of torture are rife. Many monks have been forced to denounce the Dalai Lama, who even in Songpan, where things are relatively calm, is deeply revered by Tibetans. This correspondent was often asked for news of him. “You can't call yourself a monk unless you support the Dalai Lama”, says a Songpan resident.

But Aba and Ganzi share an additional layer of resentment. Both prefectures saw the only well-documented cases of police firing on demonstrators in 2008 (20-30 people may have been shot dead in Aba town). Unlike Songpan county, where monasteries are small and scattered, Aba's main monastery, called Kirti, is large and central. Monks at Kirti have been particularly prominent in the prefecture's unrest, and the monastery is now under heavy police guard.

Woeser, a Tibetan blogger in Beijing who closely monitors the region, says the authorities inadvertently exacerbated Sichuan's instability by expelling hundreds of visiting monks from monasteries around Lhasa after the 2008 unrest. Many of these monks were from Sichuan, and they returned to their monasteries with tales of Lhasa's upheaval and the recriminations that followed. Others, barred from their original monasteries, became wandering malcontents. In Ganzi, Woeser says, passions have been stoked by the hardline fulminations of the prefecture's ethnic-Han party chief, Liu Daoping. (Aba has a Han party secretary too, as, invariably, does Tibet itself.)

The authorities have tried to intimidate Sichuan's Tibetans into giving up their protests by imposing heavy sentences on monks accused of involvement in the immolations. Free Tibet, a London-based NGO, says six have been jailed so far. Whose side the judiciary is on is clear from the title bestowed on Songpan's county court: “Advanced Collective Engaged in the Task of Opposing Separatism and Preserving Stability”. Not much subtlety or accommodation there. Sichuan's restive monks can expect no mercy.