China has executed eight people convicted on terrorism charges in the restive western region of Xinjiang, including three men authorities say were behind a deadly attack in the heart of Beijing in which an SUV ploughed through a crowd, state media reported.

Last year’s attack, in which the driver died alongside his mother and wife as passengers as well as three bystanders, was a sign that the violence the government blames on ethnic Uighur separatists was spilling out of the far western region – home to the Muslim, Turkic minority.

The others who were put to death were convicted of attacking police stations, bomb making, murder and arson, the government-run Tianshan Net news portal reported Saturday evening.

The report did not say when the executions took place.

Beijing has blamed the deadly unrest on terrorism with overseas ties, but human rights groups say the Uighurs are suffering from repressive policies and practices.

All eight people executed had Uighur-sounding names.

China has promised to strike hard against attacks in Xinjiang after scores of people were killed earlier this year. Authorities have vowed swift actions and severe punishments, but Uighur rights groups have said the harsh measures would only further alienate the minority people and cause more resentment.