At least five Colombian soldiers were killed Saturday when they crossed into a minefield while following a group of leftist rebels, the dpa reported.
Another 11 soldiers were wounded in the minefield during the operation against the Revolutionary Armed Forces of Colombia (FARC) aimed at leader Luciano Marin, alias Ivan Marquez, in the north-east province of Norte de Santander.
FARC blew up an oil pipeline in the province on Tuesday, releasing 4,000 barrels of oil in to the Tibu river from which the local population draws its drinking water.
The rebel group has been fighting the Colombian government for more than 40 years and holds hundreds of hostages.