The case highlights China’s continued fight against terrorism. One expert said the attack likely originated from China’s Uighur population, whose home lies in the western Xinjiang region across the border from Kyrgyzstan.

It’s there that Islamic Uighur separatist extremists launched attacks on the public two years ago. In response, the Chinese police have reportedly repressed any form of Islam, forcing civilians to give up fasting through Ramadan, detaining women in veils, and at times completely disabling the Internet. China’s President Xi Jinping has promised to catch terrorists “with nets spreading from the earth to the sky,” but many researchers say many innocent civilians have been caught in the crackdown, fueling resentment among locals.

Terror outside China’s orders linked to Uighurs may become a bigger concern following Tuesday’s blast. The 2015 bombing of Bangkok’s Erawan Shrine, which killed 20, was linked to the Thai government’s deportation of a group of Uighurs to China.