Beijing is vowing to strike back against an unprecedented mass killing of civilians by alleged Xinjiang militants far outside their homeland, but analysts say that may merely speed up the cycle of repression and violent reprisal.

A black-clad gang killed at least 29 people and injured more than 130 in a stabbing spree at Kunming rail station in the southwestern province of Yunnan late on Saturday.

China's top security official was quickly dispatched and urged "forcible measures to crack down on violent terrorism activities", the official Xinhua news agency said, as the public shared horror and anger at photos of bloodied bodies scattered across the floor.

Although knife and bomb attacks occur periodically in Xinjiang, where China's mostly Muslim Uighur minority is concentrated, they have rarely captured the same attention as this first large-scale killing outside the remote region.

The incident could severely harden popular and official opinion on Xinjiang -- and provoke fresh outrage as a result, said Shan Wei, a political scientist at the National University of Singapore's East Asian Institute.

"The psychological impact of this on the Chinese general public will be enormous," Shan said, adding that it would make people "more supportive of hard-line policies by the government".

"It gives the Chinese government a very strong reason to step up its hard-line policies on the Xinjiang or Uighur issue," he said.

"It's a tragedy, really, a vicious cycle."

Analysts say leaders may also feel the bloody rampage leaves them less open to the international criticism often directed at Beijing's Xinjiang policies.

Rights groups accuse China of cultural repression and discrimination in the resource-rich region. And western analysts have tended to discount Beijing's claim to be a victim of global jihad, saying it exaggerates the threat as a pretext to crack down on Uighurs.

China calls that stance a double standard on terrorism.

When a Uighur family of three drove onto Tiananmen Square last October and set their car on fire, killing themselves and two bystanders, outsiders questioned the official version of events and the "terrorist attack" label.

That incident and the Kunming attack came despite Beijing pushing a drive to develop Xinjiang after riots between Uighurs and ethnic majority Han left 200 people dead in the regional capital of Urumqi in 2009 -- though it tightened security in the region.

The following year it began encouraging investment and subsidies in the area and enhancing preferential policies toward minorities.

Xinjiang saw 11.1 percent economic growth in 2013, surpassing the national rate of 7.7 percent.

"You cannot expect that this problem can be resolved within a few years," said Shan. "You have to keep it up for maybe one decade, two decades."

Rights groups complain that the economic benefits accrue mostly to majority Han, who have settled in large numbers in the area.

Uighurs are losing out as China's economy is increasingly driven by the market, said Barry Sautman, an expert on China's ethnic politics at the Hong Kong University of Science and Technology.

"There's no doubt that there is some degree of discrimination in Xinjiang by Han entrepreneurs," he said, adding that they often prefer workers who speak the same language and do not require extra religious holidays.

On top of that, jihadist ideology outside China was having some influence in Xinjiang, he said, adding that examples of militant attacks such as those in India or Russia could easily be accessed online.

"There are some secular nationalists in Xinjiang... (but) there also are people who obviously are attracted to Wahhabi currents, Salafist currents, etc, and this is occurring all over the Islamic world so it's not unusual," he said.

Islamic extremism gained traction across Central Asia as well as Afghanistan and Pakistan after the fall of the Soviet Union.

Although China's instinct might be to crack down, Sautman urged it to expand preferential policies and autonomy, saying such measures could defuse the desire for secession.

But Renmin University professor Jin Canrong argued that China needed instead to move away from such an approach and de-emphasise Uighur identity, especially as a political notion.

They should be taught instead to identify as people of China, he said, while the status of Xinjiang -- technically the Xinjiang Uighur Autonomous Region -- should be delinked from any ethnic group.

"It used to be that China stressed very much the identity of ethnic group," he said.

"But from now on I think there will be more stress on the equal obligations and rights of citizens."

Timeline of unrest related to China's Xinjiang region
Beijing (AFP) March 02, 2014 - At least 29 people have been killed and more than 130 wounded in a mass stabbing attack at a Chinese train station, with authorities blaming separatists from Xinjiang, home to the mainly Muslim Uighur minority.

Here is a chronology of key events related to the restive region since 2009:

2009

June 25 -- Two Uighur factory workers are reported killed and dozens injured in a huge brawl with Han Chinese in Shaoguan, in the southern province of Guangdong.

July 5 -- Hundreds, perhaps thousands, of Uighurs riot in the Xinjiang capital Urumqi after security forces move in on a protest over the Shaoguan incident.

July 7 -- The government says nearly 200 people died in the unrest, with more than 1,600 injured and hundreds arrested. Eventually at least 26 are reportedly sentenced to death.

September 2 -- Han residents of Urumqi protest for days over a wave of syringe stabbings which the government eventually says had nearly 500 victims, blaming "ethnic separatist forces".

2011

July 18 -- Police kill 20 protesters in clashes in Hotan, southern Xinjiang, exiled Uighur groups say. State media say police fired on demonstrators who attacked a police station, killing one officer.

July 31-August 1 -- Two attacks by alleged terrorists leave 13 people dead in a Han Chinese section of Kashgar, while police kill eight suspected Uighur separatists.

September 15 -- Courts in Xinjiang sentence to death four Uighurs over the July incidents.

December 28 -- Police in Pishan kill seven "terrorists" in a hostage standoff that left one officer dead. State media calls them terrorists engaged in a "holy war".

2012

February 28 -- Rioters armed with knives kill at least 10 people in Yecheng, while police shoot two of the attackers dead, state press say. One man is later sentenced to death.

2013

April 23 -- Gunfights in Bachu leave 15 police and community workers and six "terrorists" dead. Two men are later sentenced to death.

June 26 -- At least 35 people are killed when, according to Xinhua, "knife-wielding mobs" attack police stations and other sites in Lukqun before security personnel open fire. Three people are later sentenced to death.

August 20 -- A Chinese policeman is killed in what state media call an "anti-terrorism" operation in Yilkiqi. Overseas media report 22 Uighurs were shot dead.

October 28 -- Three members of the same Xinjiang family crash their car into tourists in Tiananmen Square in Beijing, the symbolic heart of the Chinese state, killing two, before setting it on fire and dying themselves, according to authorities who call it a terrorist attack.

November 17 -- Two policemen and nine attackers are killed at a police station in Serikbuya, state media say. Rights groups say the trigger was the fatal shooting of a Uighur youth during a protest.

December 16 -- 14 Uighurs and two police officers are killed in Shufu county. Authorities describe the slain Uighurs as members of an extremist group, but campaigners say police raided a house where a family was preparing for a wedding, with six women among those killed.

December 30 -- An assault on a police station in Yarkand leaves eight attackers dead, according to the Xinjiang government's official website.

2014

January 15 -- A prominent Uighur academic and critic of government policy, economics lecturer Ilham Tohti, is detained by police, his wife says, and later charged with separatism, which can carry the death penalty.

January 25 -- A total of 12 people have been killed in Xinhe, six in explosions and six shot dead by police dealing with "violent incidents", a government-run news portal says.

February 14 -- A total of 11 people die in an attack on police in Wushi, with officers shooting eight dead and three blowing themselves up, authorities say.

March 1 -- At least 29 people are killed and more than 130 wounded by knife-wielding assailants at Kunming train station in Yunnan province, more than 1,600 kilometres (1,000 miles) from Xinjiang. Officials blame separatist terrorists from Xinjiang.