Colombian authorities accused the leftist FARC guerrillas Monday of forcing 19 oil tanker drivers to dump their cargo of crude on the ground, raising fears it could contaminate water supplies.

Officials said FARC fighters stopped the tankers in a dawn raid as they transported their cargo across a remote area of the oil-producing region of Puerto Asis in the southwestern department of Putumayo.

"They were apparently approached by the FARC group and forced to spill all the crude they were transporting" -- about 200,000 gallons (757,000 liters), Governor Jimmy Diaz told RCN Radio.

And the oil could affect the area's water supplies.

"This damages our natural resources and the community," the defense ministry wrote on Twitter.

The attack comes after other recent acts of sabotage attributed to the FARC in the same region, including the bombings of two electrical pylons and a water plant.

The FARC and the government have been holding peace talks since November 2012. But hostilities have intensified since the guerrillas killed 11 soldiers in an ambush in April and President Juan Manuel Santos responded by resuming air strikes on their positions.

The Colombian conflict has killed more than 200,000 people and uprooted more than six million since the Revolutionary Armed Forces of Colombia (FARC) was launched in 1964.