Authorities say police shot dead four people who detonated explosives at a Communist Party office in the far west region of Xinjiang in an attack that killed one person and injured three others.

The report in Tianshan Net, a news portal run by Communist Party officials in Xinjiang, says the incident happened Wednesday afternoon in Moyu county.

It says that four attackers drove vehicles into the county’s Communist Party courtyard and detonated homemade explosives, killing one person and injuring three others. It says police shot the four dead at the scene and called it a “terrorist attack”.

The region of Xinjiang has seen violence against civilians in recent years that authorities have blamed on radicals among the mostly Muslim Uighur ethnic minority seeking independence from Beijing.