Rescuers are searching for the missing.

Twenty-one people were left injured after a 5.8-magnitude earthquake hit northwest China's Xinjiang Uygur Autonomous Region Thursday afternoon, local authorities said Friday.

The quake rocked a border area between the region's city of Atux in the Kizilsu Kirgiz Autonomous Prefecture and Kashgar Prefecture at about 6 p.m. Thursday.

Four of the 21 injured are in critical condition, local authorities said.

The quake also toppled 147 houses and severely damaged 171 others, a spokesman with the Kashgar Prefecture government said.

No deaths have been reported in the earthquake, said the spokesman.