According to Reuters , the Regional Autonomous Corporation of Cesar, which manages environmental issues, has told Fenoco it has to stop transport runs within 100m of communities.

The quiet period extends from 11.30pm to 4.30am and agency officials said they would lift the “preventative measure … once the causes are found to have disappeared”

The ACC said in its resolution that it was seeking not to disturb residents’ sleep.

According to the report, the impact of the move is not yet known and it also is unclear if Fenoco will appeal the decision, as the agency’s resolutions are binding.

The railway has so far made no public comment on the decision.

Fenoco has an annual capacity of about 42 million tons.

The railway has had quite a trying year to date. The company’s employees went back to work in August after a 25-day strike over working conditions and pay.

In the meantime, the resulting transport stoppage paralyzed the Andean nation’s export business and also cut into production totals for whole-year 2012.

Colombia, the world’s fourth-largest coal export nation, is led by major production players Glencore, Drummond and Cerrejon, a joint venture of BHP Billiton, Anglo American and Xstrata.