(CNN) -- Police in the western Chinese region of Xinjiang have arrested 139 people for spreading religious extremism online, officials and state media said, amid a wider crackdown on internet rumors.
A spokesman for the Xinjiang government, Luo Fuyong, said that local police had gathered around 900 pieces of evidence of online rumor spreading and arrested at least 256 people.
Of those, he said 139 had spread rumors about jihad, or Muslim holy war, mainly through posting videos that showed violent terrorist attacks or taught viewers how to create bombs and explosive devices.
"Jihad and terrorists are the enemy of all human races," Luo said.
The report did not say whether those arrested were Han Chinese or Uyghurs, a Turkic-speaking predominantly Muslim ethnic group.
The arrests were made from June 26 to August 31 following an outbreak of violence in the remote township, about 250 kilometers southeast of the regional capital Urumqi, that left 35 people dead.
Frequent outbreaks of unrest have hit Xinjiang, a resource-rich region where the arrival of waves of Han Chinese people over the decades has fueled tensions with the Uyghurs.
They complain of discrimination and harsh treatment by security forces, despite official promises of equal rights and ethnic harmony.
Beijing has found it useful to portray such tensions as the result of outside interference, attempting to cast separatists as part of a global terror network since the 2001 World Trade Center attacks, said Nicholas Dynon, a researcher at Macquarie University in Australia.
This strategy undermines sympathies at home and abroad for legitimate grievances of the Uyghurs, he added.
"Conflating international terrorism with domestic separatism is way for Chinese authorities to leverage support for their own issues."
The arrests in Xinjiang come amid a nationwide crackdown on online rumors that critics have said is a way for the government to squash dissent.