Colombia’s four main illegal armed groups grew during 2023 as they consolidated territorial control financed by drug trafficking and illicit gold extraction, according to a secret security report seen by Reuters.

The report focused on the leftist guerrilla group the National Liberation Army (ELN), the crime gang the Clan del Golfo, and two dissident factions of the now-demobilized FARC rebels, the Estado Mayor Central (EMC) and the Segunda Marquetalia.

The report, produced annually, assesses illegal armed groups’ size and military might, three security sources with knowledge of the report said, adding that illegal groups often try to amplify their power for leverage at peace talks with the government, according to Reuters.

The ELN is the largest of the groups and increased its headcount in 2023 by 307 members, taking the total to 6,158. That number includes 3,305 combatants and 2,853 people who belong to support networks, according to the report, which was labeled “top secret.”

The Clan del Golfo, founded by former leaders of right-wing paramilitary groups, expanded by 23% last year, growing to 4,999 members. The group has 1,740 combatants and 3,259 support personnel, the report said.

Of the two dissident groups of the now demobilized Revolutionary Armed Forces of Colombia (FARC), the EMC is the largest, with 3,859 members – of which 2,428 are combatants.

The Segunda Marquetalia numbers 1,751, including 1,162 combatants.

The ELN, the EMC and the Segunda Marquetalia all have members in neighboring Venezuela, the report said.

Even as they grew their total headcounts, the four armed groups lost a combined 3,000 members last year, between those killed, captured or who surrendered to authorities, the report added.

“There are large and important funds that illegal armed organizations derive from activities like drug trafficking and illegal mining,” Defense Minister Ivan Velasquez said.

“This means very important profits that have allowed them to pay for recruiting people into their ranks, expanding, building structures that are intended to establish their presence in other territories,” Velasquez added.

Leftist President Gustavo Petro has promised to end Colombia’s 60-year conflict, which has killed at least 450,000 people, through peace or surrender deals with some groups.

The government is holding talks with the ELN, and both sides have agreed on a bilateral ceasefire.

A majority of the EMC has abandoned negotiations due to an internal division, though a partial bilateral ceasefire with the government continues to hold.

While the government is also preparing to begin talks with the Segunda Marquetalia in the coming weeks, the Clan del Golfo has so far rejected an offer of lower sentences for surrendering.