Two unidentified buyers told Reuters Thursday that the move was limited.

“Drummond declared force majeure only for cargoes that were in the vicinity of the loading port, which will impact a limited number of buyers in the near term,” a trader for one buyer said.

The individual told the news service that he was notified of the plan via correspondence from the producer.

A second buyer told Reuters that Drummond had already sent communications to its European and Middle East customers.

The company exports about 500,000 tonnes weekly from its two mines in the country. It also has a port facility, which is also idled due to the strike that began on July 23.

Another strike that impacted Colombian output earlier this year occurred at Cerrejon, owned by BHP Billiton, Xstrata and Anglo American.

That month-long union stoppage also led it to declare a force majeure on many of its cargoes.

Colombian law dictates that strike actions can last up to 60 days before being advanced to arbitration, where a tribunal will lift the strike.

Colombia is the largest coal producer in South America, and is also the world’s fourth-largest coal exporter.