BOGOTA (Reuters) - Roughly a third of the fighters in Colombia’s former FARC rebel army have taken up arms again following a 2016 peace accord, posing a growing security risk in the Andean nation, according to a confidential military intelligence report reviewed by Reuters.

Commander of the Colombian Military Forces, General Luis Fernando Navarro speaks during an interview with Reuters in Bogota, Colombia June 4, 2019. Picture taken June 4, 2019. REUTERS/Luisa Gonzalez

The internal report puts the number of combatants belonging to dissident Revolutionary Armed Forces of Colombia (FARC) groups at around 2,300, a sharp increase from about 300 at the time of the controversial peace agreement.

With the signing of the accord, almost 13,000 members of the FARC, including more than 6,000 fighters, handed in their weapons to be destroyed and ended their part in a five-decade war that killed over 260,000 people and displaced millions.

The report said there were 31 dissident FARC groups operating in regions that grow coca - the raw material for cocaine - and in areas of illegal gold mining. Colombia is the world’s largest producer of cocaine. The estimate of dissident fighters showed a roughly 30% increase from the previous official tally in December.

“If you look at where these organized armed groups are or where they’ve appeared, it’s associated with crime: where there’s a high presence of drug trafficking or illegal mining, or in border areas, especially near Venezuela,” General Luis Fernando Navarro, commander of Colombia’s military forces, told Reuters on Tuesday.

The FARC political party that formed in the wake of the peace deal has said that, in addition to pressure to join dissident groups engaging in illicit activities, former fighters were taking up arms due to frustration over a lack of economic opportunities and anger over stigmatization and violence against them.

President Ivan Duque has sought to alter the peace accords -- which won former President Juan Manuel Santos a Nobel Peace Prize -- because he says they are far too lenient on the FARC, which engaged in decades of kidnapping, drug trafficking, extortion and killing.

A high-profile attempt to extradite former FARC commander Jesus Santrich to the United States on drug trafficking charges has so far failed, but caused anger among other FARC leaders who say Duque wants to jail them at any cost despite the agreements. [nL2N2351KN]

Sergio Guzman, director of Colombia Risk Analysis, a Bogota-based political risk consultancy, said government attempts to “reinsert” former rebels back into civilian life had been stymied by violence and discrimination and the failure of some employment projects created in tandem with the peace accord.

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“It doesn’t help the government’s case for reinsertion that many of the productive projects are failing to take off, their former comrades continue to be stigmatized by the ruling party, and a record number of killings of former FARC members remains uninvestigated and unpunished,” Guzman said.

The government has said it supports 186 individual and collective projects that benefit 1,404 ex-combatants with investments of more than $4 million. Some of the projects are in areas where the FARC previously had an armed presence.

Leaders of the Revolutionary Alternative Common Force, which shares the FARC acronym and is the political party formed after the peace accord was signed, have warned that the killings of 139 former combatants have also driven the increase in dissent.

They have blamed right-wing paramilitary groups for many of the killings.

The military document also showed the number of fighters in the leftist rebel National Liberation Army (ELN) has increased by nearly 8% to 2,400 since the end of last year.

The ELN held peace talks with Santos’ government but Duque canceled them indefinitely after a January bomb attack in Bogota claimed by the armed group.

Now, the military intelligence report says, 45% of the ELN’s fighters - including its commanders - are hiding in neighboring Venezuela and receiving protection from Venezuela’s left-leaning President Nicolas Maduro.

Venezuela’s Socialist government has over the years acknowledged that the ELN enters the country but denies supporting the rebel group.

“The ELN considers Venezuelan states bordering Colombia as their strategic rearguard,” said Navarro, adding that growth in the ELN and FARC ranks was “a risk and we have to contain them.”

The leftist government of Venezuelan President Nicolas Maduro is engulfed in a deep political and economic crisis after opposition leader Juan Guaido cited the constitution in January to announce an interim presidency.