Bogota - Eight Colombian soldiers were killed Wednesday when they stepped into a mine field as they fought leftist rebels in south-western Colombia.

Army spokesmen said a sergeant and seven enlisted soldiers died in the incident outside the municipality of Barbacoas, in the Narino province, on the border with Ecuador.

The radio network Caracol quoted Brigadier General Leonardo Barrero as saying that the mine field had been set up by the leftist Revolutionary Armed Forces of Colombia (FARC).

Reinforcements were sent to the area in an effort to find the rebels responsible.

In recent years Narino has become a one of the country's main producers of coca, whose leaves constitute the raw material for cocaine. Production of poppy, from which heroine is made, is also widespread.

Moreover, key routes for drug trafficking and weapons smuggling pass through the province on the Pacific coast.

FARC increasingly finance their activity through the drug trade, and they try to prevent the destruction of their drug-related crops through mine fields. (dpa)