China Xinjiang blast killed 31 people, 90 injured: Report

Uighur activists say the violence is being fueled by restrictive and discriminatory policies and practices directed at Uighurs and a sense that the benefits of economic growth have largely accrued to Chinese migrants while excluding Uighurs.

The knowledge that Muslims elsewhere are rising up against their governments also seems to be contributing to the increased militancy.

Thursday's attack came two days after courts in Xinjiang sentenced 39 people to prison after being convicted of crimes including organizing and leading terrorist groups, inciting ethnic hatred, ethnic discrimination and the illegal manufacturing of guns.

Among those convicted Tuesday was 25-year-old Maimaitiniyazi Aini, who received five years in prison for inciting ethnic hatred and ethnic discrimination for comments he made in six chat groups involving 1,310 people, the Supreme Court said.

In another case, a Uighur man was jailed for 15 years after he preached jihad, or holy war, to his son and another young man, according to the court.