Zhang Chunxian, right, Party chief of Xinjiang Uygur autonomous region, attends a plenary meeting of Xinjiang legislators to the 12th National People's Congress, on March 10, 2015. [Photo/Chinanews.com]

Zhang Chunxian, the top official of the Xinjiang Uygur autonomous region said on Tuesday some Xinjiang people have crossed the border illegally to join Islamic State (IS).

"The organization has growing international influence and Xinjiang is affected by it. We've busted a terrorist cell in Xinjiang run by those who have returned from fighting with the organization," said Zhang, Party chief of the terror-affected region in Northwest China.

He added that IS is a threat to the world and requires joint international efforts to fight it.

"Some people in Hotan prefecture in southern Xinjiang have been influenced by IS," said Eziz Musar, the prefecture's commissioner. "That influence is also felt in other parts of the region."

External extremist forces use the Internet to spread their ideas, fan hatred and propagate terror, Eziz said. Messages are downloaded by a very small group of local people who pass them on to others.

"Authorities have to put this extremist content on their watch list and enforce the law by accelerating the crackdown on those who spread such illegal information," Eziz said.

The overall situation in the Xinjiang Uygur autonomous region remains stable and controllable, said another senior official.

"Violent terror attacks have provoked strong condemnation and opposition in the region," said Shohrat Zakir, chairman of the Xinjiang regional government, at a panel discussion during the ongoing annual session of the National People's Congress.

With the efforts of people from all ethnic groups, violent terrorist crimes were cracked down on in accordance with the law and the sanctity of law was safeguarded, he said.

"A number of violent terrorist attacks were thwarted while they were still in the embryonic stages," he said. "There will be fewer and fewer, rather than more and more, violent terrorist cases".