Locals from the northern mountainous province said an earthen dyke holding back industrial sludge produced by Na Lung Factory (owned by Cao Bang Minerals and Metallurgy Company) broke.
Many trees and animals were killed and residents are anxious about the impacts of the mud on their health.
Ma Thi Bach, a local resident, said she rushed home after hearing that her home had been flooded.
“It came so fast… I could only manage to take my TV and some clothes," Bach said. "In a moment, the mud was over my knees and I couldn’t take any more things. Dozens of my chickens were killed.”
The incident left a layer of knee deep sludge on the road, making travel difficult.
Nguyen Van Tuc said the sludge filled his well and buried the rice paddies of several neighbors.
The company has used cranes to clear mud from the roads and clean people’s houses with pumps. The job is expected to take more than a couple days.
But Bach said the matter is not simply to clear the mud.
“This is not the normal mud,"she said. "It is the mud from an iron ore plant; it could contain chemicals, heavy metals that are poisonous to us, our plants and animals.”
Le Ngoc Quang, a local commune official, said Na Lung factory has spilled industrial sludge out into the community several times before, and it has, as many times, promised to stop the problem.
Since it started operation in 1990s, water at a main stream in the area turned red and fish died, locals said. The stream joins the local Bang River.
One member of the red-eared slider turtle species has been spotted in Kien Giang Province, after Mekong Delta governments have made several efforts to stop the foreign invasive reptile from spreading.