Columbia ? Government troops have retaken control of an area in southern Colombia where leftist rebels ambushed and killed 15 soldiers, the president said Sunday.

The soldiers were ambushed Saturday after the military learned guerrillas planned to seize the remote hamlet of La Julia, 100 miles south of the capital.

“This hurts immensely and that’s why we must get rid of forever the drug trade which is financing these terrorists,” President Alvaro Uribe said. He spoke before boarding a plane to visit troops in the northeastern state of Norte de Santander, another area hard hit by guerrilla violence.

After the military received warnings of the impending assault on La Julia, a mobile army unit from the U.S.-trained Omega Force was dispatched Saturday to the area.

The area is the main stronghold of the Revolutionary Armed Forces of Colombia, or FARC, said Gen. Freddy Padilla, chairman of Colombia’s Joint Chiefs of Staff. He said his troops were surprised by the rebels.

The FARC has been trying to overthrow Colombia’s government for almost a half-century.