Frost and icicles cover the Shizuishan Environmental Protection Bureau in Ningxia Hui Autonomous Region. Photo: Beijing Time

Two Northwest China officials were punished after their plan to reduce air pollution readings by spraying water cannons near monitoring equipment backfired and left a government building encrusted in ice.Frost and icicles covered the Shizuishan Environmental Protection Bureau in Ningxia Hui Autonomous Region after water cannons passed the building's main entrance overnight, recent photos showed.The two officials had ordered sanitation workers in December to spray the building, which houses a national air quality monitoring site, media reported.Mao Junfeng, director of the local sanitation station, and his vice-director Cai Tianming were issued "public warnings," read a Shizuishan government statement.Provincial environmental protection authorities said that Mao and Cai were seeking to reduce air particle readings by spraying water around the sensors in order to meet air quality standards.Sanitation workers continued to spray the environmental protection building on Mao and Cai's orders to deliberately reduce pollution readings, a release from the environmental bureau read Tuesday."Their dust-control methods were not professional and they affected air quality data," read the statement.

Left: Sanitation workers use water cannons to spray the building at night. Right: The building is covered in frost and ice the following day. Photo: Beijing Time