A sea of mud and water released by a broken dam which had been built to hold earth from an iron-ore mine swamped houses and paddy fields in a commune in the northern mountainous province of Cao Bang on Nov. 7.

Some workers, who do not wish to be identified, have said the mud was often illegally discharged at the bottom of the dam into the nearby Bang River .

The local People's Committee held an urgent meeting after the thousands of cubic metres of sludge broke loose.

It is calling for strict punishment against the Na Lung iron ore mine, owned by the Cao Bang Minerals and Metallurgy Company.

The mud flow inundated many houses and fields in Duyet Trung commune and covered roads.

Roads to the mine are still blocked, but the mining company is using cranes to clear the mud and cleaning waist-deep mud from houses with pumps.

However, the job is expected to take more than two months to complete.

Chairman of the People's Committee Nguyen Hoang Anh told factory owners to pay rent support to two of the most seriously affected families.

He also told it to compensate farmers for 6ha of agricultural land buried under the mud.

Anh also asked them to build a temporary bridge to enable the traffic to flow and ordered them to prevent any more mud from being released - or escaping - into the river to prevent environmental pollution.

He said the factory would be shut down if it continued to violate environment regulations.

Ma Thi Bach, a resident of Na Keo hamlet in Duyet Trung commune, said her house was still submerged under 1.5 metres of mud after the water went down.

She and her family have had to move to a small tent.

Another resident, Nguyen Van Tuc, said the sludge filled his well and buried the rice paddies of several neighbours.

The head of the Natural Resources and Environment Department's inspectorate, Le Hong Hai, said the mine admitted the dam, built in 2005, was not strong enough.

However, some workers said the problem was caused by a big drain at the bottom of the dam used for discharging waste sludge into the river.

Hai said the mine was fined 70 million VND (3,500 USD) for discharging illegal waste sludge in 2008. He added that they tried to let it out before flood season.

Deputy head of the provincial Environment Protection Department Doan Ngoc Bau said the dam had been built without permission.

Bau said the department had fined the factory for not providing a design and environmental impact report on the dam - and still had not completed it.

The mine once applied for a permit to build the dam with a total investment of 30 billion VND (1.5 million USD), but it was rejected because there was no environmental impact report.

The only good news about the mud flow was that it was not toxic, like the mud produced at bauxite mines, said vice chairman of the People's Committee Nong Van Pao./.