China's President Xi Jinping ordered a crackdown on "violent terrorist activities" after 33 people died when knife-wielding assailants rampaged through a train station in a southwestern city Saturday.

Local authority officials in Kunming said evidence at the scene showed it was a terrorist attack orchestrated by Xinjiang separatist forces, the state-run Xinhua News Agency reported. An exiled group promoting human rights for the region's minority people, the Uighur, called for a transparent investigation.

The assault, days before the annual meeting of the legislature in Beijing, highlights growing social unrest amid widening inequality and increasing tensions between the state and some ethnic groups including the mostly Muslim Uighur minority in Xinjiang. The ruling Communist Party last November set up a state committee to better coordinate security issues as it faces dissent at home and expands its military reach.