BOGOTA – Colombia’s biggest coal producer, Cerrejon, said a bomb attack on its railway on Sunday partially derailed a train carrying coal to port and damaged the track, but exports would continue as normal using stocks held at its privately-owned port.

The early-morning attack, which a military source told Reuters was carried out by the country’s main rebel group, the FARC, was the latest in a spate of explosions in the last week blamed on the guerrillas and targeting oil and gas pipelines.

The railway owned and used exclusively by Cerrejon, carried 32.7 million tonnes of coal from its mine in La Guajira province to its port, Puerto Bolivar in 2012, the company said. Cerrejon is a joint venture between Anglo American, BHP Billiton and Xstrata.

A Cerrejon team was working with the security forces to secure the area where the explosion took place and carry out necessary repairs to re-open the line, a company statement said.

Juan Carlos Restrepo, a company spokesman, told Reuters it was unclear how long it would take to reopen the rail line, but said stocks at the port would cover export requirements until it reopened.

“Cerrejon condemns this type of violent action that generates considerable economic and environmental damage and at the same time creates a high risk of fatalities,” Cerrejon’s statement said.

The explosion was a further setback to the company this year and to Colombia’s coal sector as a whole after a month-long strike by Cerrejon workers in February followed by a seven week stoppage at Colombia’s No. 2 miner, Drummond.

Cerrejon’s property was subject to seven attacks in 2012. The company did not blame any specific group for the attack and said no one had been injured.

The FARC and their smaller counterpart, the ELN, regularly attack infrastructure in the energy sector in protest at the presence of foreign companies whose activities they say do not sufficiently benefit the Colombian population.

Though attacks continue, security for businesses has vastly improved since a U.S.-backed offensive against anti-government guerrillas and drug gangs was launched in 2002.

That has helped attract billions of dollars in new investment as explorers push into more areas in search of minerals and oil. In 2012, Colombia brought in $16 billion in foreign investment, up from around $2 billion in 2002.