The number of violent attacks by "terrorist cells" in China has dropped due to increased security measures, state media reported on Tuesday, however it also cited experts as saying the level of attempted violence remains high.

China says it faces a serious threat from violent extremism, particularly in its western region of Xinjiang, where hundreds of people have been killed in recent years in unrest between mostly Muslim ethnic Uighurs and majority Han Chinese.

Officials say there is a campaign by separatists there who want to set up an independent state called East Turkestan. However, rights groups doubt the existence of a coherent militant group in Xinjiang and say Uighur anger at repressive Chinese policies is more to blame for the unrest.