Zhang Chunxian, party head in Xinjiang, told reporters that the radicals were caught when a terror plot was recently uncovered, reported the Global Times, which is affiliated with the ruling party mouthpiece People's Daily.
He said that they had returned to Xinjiang, the homeland of China's Uighur ethnic minority, to participate in violent terror plots, the report said. He apparently gave no details, including the number of people apprehended.
Other Chinese media carried similar reports, but did not specifically mention Syria.
Xinjiang, in far western China, has seen a wave of unrest, labelled by authorities as "terrorism" and blamed on "separatists", which has sometimes spread to other parts of the country.
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Among the most shocking attacks was a deadly rampage by knife-wielding assailants at a train station at Kunming in China's southwest in March, when 31 people were killed and four attackers died.
More than 30 people were killed in an assault on a market in the Xinjiang regional capital Urumqi in May, prompting China to launch a crackdown, detaining hundreds of people described as suspected terrorists.
China regularly accuses what it says are exiled Uighur separatist groups such as the East Turkestan Islamic Movement and the Turkestan Islamic Party of being behind attacks.
But overseas experts doubt the strength of the groups and their links to global terrorism, with some saying China exaggerates the threat to justify tough security measures in Xinjiang.
Rights groups say that harsh police treatment of Uighurs and government campaigns against religious practices, such as the wearing of veils, has led to violence.