The recent violence that jolted northwest China's Xinjiang Uygur Autonomous Region shows marks of religious extremism, which -- if not effectively checked -- will continue to fuel bloody attacks throughout the volatile and ethnic-diverse region, Chinese experts say.

"The violence in Xinjiang is starting to resemble the terrorist attacks in neighboring Afghanistan and Pakistan," said Yang Shu, professor with Lanzhou University and long-time Xinjiang observer. "The attackers are deeply influenced by thoughts of ethnic and religious extremism."

"They are operating in small clusters, usually made up of family or friends, and are increasingly willing to carry out suicide attacks," said Yang, head of the Institute of Central Asian Studies at Lanzhou University.

Xinjiang -- with 41.5 percent of its 21 million population Uygurs, a largely Muslim Chinese ethnic group -- is at China's frontline against separatism, extremism and terrorism. Separatist militants cross the border to terrorist camps in Afghanistan and Pakistan for training before returning to carry out attacks, experts say.

Beijing-based researcher Ma Dazheng, who is with the Chinese Academy of Social Sciences, said the security situation in Xinjiang has become more complicated and the authorities face mounting challenges as extremists are becoming bolder, and their attacks more brutal.

Ma said while there had been outbreaks of unrest in Xinjiang for decades, suicide attacks were rare in the past. He added that in the 1990s such attacks on the public were mostly carried out at night and attackers quickly vanished after their raids.

Today, Xinjiang's attackers boldly commit acts of terrorism in the open.

Yang also noted that separatists and religious extremists increasingly conduct attacks in medium-sized cities rather than just small and remote towns.

Three separate attacks were carried out in the urban areas of two cities in Xinjiang over the past two weeks. Fourteen civilians were killed, 42 injured by knife-wielding assailants in a pair of attacks in the city of Kashgar last weekend. Eight suspected attackers were shot dead by police in the clashes.

The government authorities classified Sunday's attack as an act of terrorism and said the attackers were a group of religious extremists led by overseas-trained militants of the "East Turkistan Islamic Movement" (ETIM), a terrorist organization recognized by both Beijing and the U.N.

The Kashgar attacks came soon after another deadly clash in downtown Hotan on the southern edge of the Taklamakan Desert. On July 18, a mob stormed a police station, hurled burning gasoline cylinders into rooms, took hostages, and attacked people indiscriminately with axes and knives. Eighteen people, including 14 attackers, were killed in the clash.

According to a police account, the attackers fought against police as they attempted to fly a flag with religious slogans on the flag pole on top of the police building. Captured attackers admitted to police investigators that they had attempted to rally support and stir up ethnic tension.

A local anti-terrorism expert who declined to be named told Xinhua that the government leadership must curb the spread of extremism among local religious believers.

He said the extremists took the advantage of the government's policy on religious freedom and were indoctrinating people with extremism through underground preaching.

At an emergency meeting held in the regional capital Urumqi following the attacks, Zhang Chunxian, secretary of Xinjiang regional committee of the Communist Party of China (CPC), ordered a crackdown on terrorist activities, religious extremist forces, and effectively check "illegal religious activities."

Zhang also ordered strengthened management of explosives.

"People in Xinjiang should stay vigilant and recognize that terrorist attackers are the 'common enemies of all ethnic groups,'" Zhang said.

Long battle

Xinjiang has barely recovered from a deadly riot in Urumqi two years ago, the worst outbreak of violence seen in the region in decades. On July 5, 2009, a large number of rock-flinging and knife-wielding thugs looted shops, torched vehicles and killed nearly 200 people in the city's downtown areas.

The authorities blamed overseas cessionist groups for inciting the unrest. Tensions sowed by the riot still linger.

Pan Zhiping, head of the Institute of Central Asia Studies with the Xinjiang Academy of Social Sciences, described the recent violence as "aftershocks" of the Urumqi riot, as locals believe that many of the thugs who fled after taking part in the 2009 riots have returned.

Local security officials disclosed that they had broken up five violent gangs which had the potential to carry out acts of terrorism during this year's riot anniversary on July 5.

But Pan said the recent outburst of violence did not mean the situation in Xinjiang had further deteriorated.

Last year the central government drew a set of favorable policies from tax cuts to job creation for Xinjiang and mobilized nationwide financial and talent support to boost the region's economic development.

"With favorable policy and development momentum, Xinjiang is moving towards prosperity and stability. The bout of violence won't reverse the trend," Pan said.

But experts said it would take a long time for Xinjiang to completely remove the stability threats.

Yang said it would be premature to hail a marked improvement of security in Xinjiang only one year after the central government's aid policy, after separatist movements have been active here for almost a century.

Studies show the "East Turkistan" forces, with the aim of splitting Xinjiang off from China, had appeared as early as in 1930s to 1940s in the region and turned extremely violent in the 1990s. The "East Turkistan" forces were said to be responsible for at least 200 violent attacks in Xinjiang between 1990 and 2007.

"The government should take control of the situation first and gradually implement measures to make meaningful changes," Yang said. "We are not talking about 20 years but much longer than that, to see the change."