The dramatic failure of China’s containment strategy for a long-running insurgency in the remote northwestern region of Xinjiang poses a grave policy challenge for Beijing.

The conflict, involving Muslim Uighurs who object to Chinese control of their energy-rich homeland, burst into the country’s heartland in a terrorist attack that claimed the lives of 33 people in the southwestern city of Kunming on Saturday night. The deadly assault by machete-wielding assailants, who struck at the city’s main railway station, also raises questions about whether the Chinese government’s hardline response to Uighur “separatism” has succeeded only in creating a more intractable crisis.

Last night the official Xinhua news agency said Chinese police had arrested three people involved in the attack and identified the group’s leader as Abdurehim Kurban. Authorities killed another four suspects and apprehended a fifth at the railway station on Saturday.