A cold front has caused a 210-kilometer (130-mile) stretch of China's Yellow River to become clogged with ice, forcing authorities to sound a flood alert, state media said Saturday.
The ice jam is concentrated in the Ningxia Hui region in the northwest of the country, the Xinhua news agency reported.
In response, the Ningxia Flood Control Headquarters has ordered cities along the river to do what they can to remove ice and other obstacles.
If that fails, the cities are to make necessary preparations to fight the floods that may result, the agency said.