URUMQI - 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 pm 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.