Trucks haven been attacked with explosives during a Colombian mine strike.
Protesters detonated explosives in the early morning attack on the Cerrejon coal mining venture jointly owned by BHP, Xstrata, and Anglo American.
Four trucks were damaged during the seventeenth day of the strike, Bloomberg reported.
The company has said it loses $US3 million ($A2.94 million) every day the workers are on strike.
Nobody has been killed and it is still not clear who was targeting the vehicles, Cerrejon said in a statement.
“Cerrejon emphatically rejects the act of terrorism carried out against it.
"There were no human losses as a result of this terrorist action, but four of the company's trucks that were parked due to the 17-day strike were seriously damaged," Cerrejon said in a statement.
“Cerrejon calls upon its workers and the community for solidarity in condemning these acts.”
5,000 Cerrejon employees walked off the job on February 7 following an ongoing dispute over pay rises.
Igor Diaz, president of the Sintracarbon coal workers’ union, told Bloomberg that his group condemns the terrorist attack and that his union plans to re-engage mine leadership tomorrow in a step toward resolving the dispute.
“We completely reject this terrorist attack,” he said in a Bloomberg telephone interview.
"It's a lamentable act that we emphatically reject," Diaz wrote on Twitter.
Located in the north near the Venezuelan border, Cerrejon is Colombia’s top coal producer; this strike has frozen all the company’s exports.
Its largest competitor Alabama-based Drummond Co., is also unable to export coal at this time.
Drummond's port operating license was suspended earlier this month following an environmental incident where the company dumped "about 300 tons" of coal into the Caribbean Sea in an effort to prevent one of its barges from sinking, Fox Business reported.
With both the country’s big coal exporters temporarily sidelines, Colombia is only exporting one-fifth of what it ships on a normal day.
Colombia is among the top ten coal producers in the world; it is in the top five coal exporters globally with most of the resource going to Europe.
Prices for coal in Europe were relatively stable last week, prompting some analysts to announce the market has an excess supply.