A new guerrilla attack on Colombia's Caño Limon-Coveñas pipeline, out of service since March 25, has caused an oil spill and sparked environmental concerns.

Friday's attack in the central province of Boyaca poses a potential public-health emergency, Cubara Mayor John Jairo Alonso said, warning that the spilled crude could reach nearby rivers.

The environmental damage is affecting local communities and the inhabitants of the nearby northeastern provinces of Arauca and Norte de Santander, Alonso told reporters.

As a preventive measure, authorities have prohibited the consumption of water in the Agualinda region until the situation is brought under control.

The attack, blamed on National Liberation Army, or ELN, guerrillas, comes a day after the U'wa indigenous community reached an agreement with the government to end their protest and allow technicians on their lands to repair another nearby section of that same conduit that was damaged on March 25.

That 770-kilometer-long (480-mile-long) pipeline transports oil from the Caño Limon fields in the northeastern province of Arauca to the Caribbean port of Coveñas.

The ELN and the larger Revolutionary Armed Forces of Colombia, or FARC, guerrilla groups carried out 33 attacks on that conduit and the Bicentenario pipeline, located in the same region, in the first three months of 2014, according to Colombian state-controlled oil company Ecopetrol.

The FARC and Colombia's government have been holding peace talks in Cuba since November 2012. EFE