Special forces search for "terrorists" during a drill in Nanning, Guangxi. Huo Yan / China Daily

Illegal exit and entry

The Ministry of Public Security said that in recent years a number of violent suspects and extremists from the Xinjiang Uygur autonomous region have illegally entered Southeast Asian countries, including Vietnam, Thailand and Malaysia, en route to battle zones.

When they arrive, the suspects obtain fake passports that allow them to travel to Turkey and then Syria, Iran or Pakistan, where they join extremist organizations and receive military training before returning to China to plan attacks, according to the ministry.

Officials from the Counterterrorism Department highlighted the fact that, aided by ETIM, Chinese extremists cross the border illegally in areas such as Yunnan province and the Guangxi Zhuang autonomous region and then make contact with locals who help them to enter other countries in the region.

When they arrive in Turkey, the extremists are recruited by ETIM, which selects hardliners to enter Syria via the Turkish border. "These people generally fight in Syria for two or three months and then return to Turkey," the official said.

After the number of illegal border crossings soared at the start of last year, the ministry launched an eight - month crackdown in China's four major border regions, including Guangxi and Yunnan.

Statistics from the ministry show that in 2013, police in Yunnan and Guangxi uncovered 100 cases of illegal immigration and arrested 795 suspects, a sevenfold rise from 2012.

Between April last year and January, police in the four border regions discovered more than 260 cases of illegal cross-border activity and also arrested more than 350 people suspected of organizing the crossings, along with 852 people who were attempting to enter another country illegally.

In January, police in Guangxi shot and killed two suspects from Xinjiang who reportedly attacked the officers with knives as they attempted to cross into Vietnam illegally.

"Extremists from Xinjiang have colluded with foreign accomplices to conduct organized illegal emigration," said Dong Xiaogang, deputy director of the ministry's Criminal Investigation Bureau.

"Gang members always undertake different tasks to form a complete chain, including recruiting the extremists, transportation, illegal immigration and handling fake passports," he said.

According to the counterterrorism department, the situation in war-torn Syria has provided a wider sphere of action and practical training for terrorists, and extremist organizations have used the conflicts in Syria and Iraq to expand their activities and recruit new members globally.