BOGOTA – Four FARC guerrillas, including the commander of the insurgent group’s 10th Front, were killed when the armed forces bombarded their camp over the weekend near Colombia’s border with Venezuela, Defense Minister Rodrigo Rivera said.

The armed forces bombarded at least two Revolutionary Armed Forces of Colombia, or FARC, camps outside Arauquita, a city in Arauca province, Rivera said.

“They are telling me at this time that it was alias ‘Efren,’ who is the top leader of the FARC in the entire area,” Rivera said, adding that “we cannot confirm or rule out that he was among the dead.”

The armed forces attacked the camps on Saturday afternoon and officials are trying to identify the bodies found in the area, one of which may be that of Efren Arboleda, whose real name is Luis Eduardo Lopez Mendez.

Arboleda is a close associate of German Suarez Briceño, the brother of the FARC’s military chief, Jorge Briceño Suarez, known as “Mono Jojoy,” who was killed in an airstrike on Sept. 23.

About a ton of powerful explosives were found at the FARC camps outside Arauquita.

“I congratulate the armed forces for the new blow against the FARC in Arauca,” President Juan Manuel Santos said in a Twitter posting.

Army troops, meanwhile, prevented two attacks by the FARC in the southern province of Caqueta.

Soldiers found four bombs on the road that leads from the city of San Vicente del Caguan to Puerto Rico, the army said.

The FARC, Colombia’s oldest and largest leftist guerrilla group, was founded in 1964, has an estimated 8,000 fighters and operates across a large swath of this Andean nation.

The Colombian government has made fighting the FARC a top priority and has obtained billions in U.S. aid for counterinsurgency operations.

A succession of governments have battled Colombia’s leftist insurgent groups since the mid-1960s.

In 1999, then-President Andres Pastrana allowed the creation of a Switzerland-sized “neutral” zone in the jungles of southern Colombia for peace talks with the FARC.

After several years of fitful and ultimately fruitless negotiations, Pastrana ordered the armed forces to retake the region in early 2002. But while the arrangement lasted, the FARC enjoyed free rein within the zone.

The FARC is on both the U.S. and EU lists of terrorist groups. Drug trafficking, extortion and kidnapping-for-ransom are the FARC’s main means of financing its operations. EFE