Workers clean the oil slick along the Xijiang River near Foshan city in Guangdong Province on Saturday. [Photo: Guangzhou Daily]

A two-kilometer-long oil slick at the Foshan section of the Xijiang River in Guangdong Province is threatening the local water supply, the Guangzhou Daily reported on Sunday.

To ensure a clean and stable water supply for local residents, the water company of Gaoming district in Foshan city stopped pumping water from the river for more than six hours. Up to 3 o'clock in the afternoon on Saturday, the water company restored water supply.

Now, most of the oil slick has been cleaned up. And the cause of the oil slick is still under investigation.