A total of 8.5 metric tons of industrial salt used as a snowmelt agent has gone missing in Nantong, Jiangsu province, China News Service reported on Friday.

Nantong's Highway Administration Office asked whoever took the industrial salt to return it and warned that it is not edible. Local police have also started an investigation.

Heavy snow hit the coastal city in eastern China on Wednesday night and the local road management authority began to spray the snowmelt agent. However, the industrial salt stored by the road side was reported missing in six of the city's eight subordinate administrative regions, said an official surnamed Sun.

All the missing salt was marked as "not edible" on its packaging, but the office is still worried that it might be used for cooking, Sun said.

Nantong's road management office prepared more than 200 metric tons of industrial salt before the snow came, according to a report on the web portal owned by Nantong Daily.

Li Shun contributed to this story.