Chinese officials said Tuesday that members of the country's Muslim Uighur ethnic minority have gone overseas to fight with the Islamic State group, which controls sections of Syria and Iraq, and returned to take part in plots at home.

Authorities in the far-western region of Xinjiang, which borders Afghanistan and Pakistan, will strengthen their crackdown on terrorism and extremism as a result, regional representatives said at a discussion on the sidelines of China's legislature.

Xinjiang has seen repeated violence as members of the Muslim Uighur minority group have bristled under what they say is repressive Chinese government rule. Attacks blamed on Uighurs have also occurred in other parts of the country, including a car which plowed into Beijing's Tiananmen Gate in 2013, killing five people.

"There are Uighurs that have fled overseas and joined the Islamic State," said Zhang Chunxian, Communist Party secretary of Xinjiang. "The organization has a huge international influence and Xinjiang can't keep aloof from it and we have already been affected. We have also found that some who fought returned to Xinjiang to participate in terrorist plots." He didn't elaborate.

Beijing has previously blamed the violence on Islamic militants with foreign connections who are seeking an independent state in Xinjiang, but has offered little evidence and ignored calls for independent investigations. Uighur groups say police have used indiscriminate deadly force against people protesting the government's policies in the region.

The Global Times, a newspaper affiliated with the ruling Communist Party, said in December that about 300 Chinese are fighting alongside the Islamic State group in Iraq and Syria.

Zhang said authorities would take measures to stop people from going abroad to fight with the group, and that he expects "fewer and fewer cases" of that happening. "We are confident that we can fix it," he said.

Another official, Shohrat Zakir, said a yearlong crackdown on terrorist activities in the region "has won wide support from people of all ethnic groups."