An explosion has rocked a tax office in central China, killing at least four people and injuring 19.
The official Xinhua news agency said the explosion occurred at a district tax office in Changsha, capital of Hunan province, on Friday afternoon.
Initial investigations show it was a planned attack, Xinhua says, citing a statement by the city's police department.
The Chinese authorities are struggling to contain social tensions, and anger over issues ranging from the cost of healthcare to a rapidly widening rich-poor gap has in the past given rise to acts of violence.
