BOGOTA (November 8, 2012)--Ten peasants have been killed by a drug-trafficking paramilitary group in a northeastern region of Colombia, officials said.

The massacre was carried out by members of a group known as "Los Rastrojos" who stormed into a tomato farm at around 6 p.m. local time on Wednesday.

The group killed nine men and a woman in the municipality of Santa Rosa de los Osos located in the state of Antioquia, said Santiago Londono, government secretary for Antioquia.

Local media said a grenade killed the farm laborers, but officials are still investigating.