Acid water from Peru's Yanacocha gold mine leaked into local irrigation canals after the tube conducting the acid water to the treatment plant was set on fire by unknown individuals, according to a statement from the mine.
Some 15m of the tube was totally burnt, said Yanacocha, Latin America's largest producing gold mine with forecast 2006 output of roughly 2.5Moz.
The apparent sabotage was discovered after canal users alerted Yanacocha on October 13 that the irrigation water was an unusual reddish color.
"As soon as Yanacocha became aware of the incident it put in place contingency measures to control the leak," the statement said.
The mine is working with the users of the Quishuar and Encajón-Collotán canals to evaluate water quality and to discover who was responsible for the action.
Yanacocha has faced over recent years a barrage of opposition from local communities around the mine in northern Peru's Cajamarca department, with many particularly concerned over the operation's impact on water quality.
"Yanacocha will not overlook any malicious act that tries to impact the environment and the good relations between Yanacocha and its neighbors," the statement said.