The land and water resources of a village in Nanjing, Jiangsu Province were heavily polluted by secretly discharged waste water from seven nearby companies, but the waste has not likely affected the water quality of the Yangtze River, local environmental authorities said.

Separated from the Yangtze River by a single dike, the village's ditches are full of milky white and dark green waste water, and give off noxious odors, the Yangtze Evening Post reported on Wednesday after receiving complaints from nearby residents.

"The water is toxic. When a mouse fell into the ditch, it died after turning a somersault," residents told the Yangtze Evening Post.

"The water and soil have been polluted with heavy metals and all the polluting companies in Lianmeng village, Qixia district, have been closed down," an official from the Nanjing Environmental Protection Bureau, surnamed Shao, told the Global Times on Thursday.

"They were electroplating and chemical companies. The major pollutants in their industrial waste were heavy metals," Shao said.

Shao emphasized that the ditches are not the source of drinking water for local residents. The polluted water has caused damage to farmland and fishery ponds, and probably also threatens the quality of groundwater, Shao said.

A special team was sent to further investigate the companies. The team is also supposed to set up a program to rehabilitate the soil and water in the area, but the officials, reached by the Global Times on Thursday, wouldn't reveal details of the process.

Shao denied the polluted water has flowed into the Yangtze River, saying the pollution is confined to "almost dead water in a relatively closed area."

"When the team went to investigate, they didn't find any sign that waste water was discharged into the Yangtze River and affected the quality of the river," Shao said.

The residents didn't agree with the statements by the authorities.

In order to prevent filth from flowing onto cropland and into ponds, residents frequently pumped the waste water to the Yangtze's riverbank, the Yangtze Evening Post reported.

Residents said that everyone knew this would directly pollute the Yangtze River, but they didn't have a better choice. The stones on the riverbed became yellow, and residents assume this was caused by the waste water.

Shao and other officials from the city and district environmental protection bureaus refused to reveal whether the authorities had received complaints about pollution from these companies before the waste was reported by the media.

Early this year, the bureau ordered the seven companies to close down before May, in order to rectify their waste management systems, Shao said.

She declined to say whether supervision from authorities was implemented after the order, ensuing the companies would not pollute the environment nearby.