The United States on Thursday offered rewards of up to $10 million for the capture of two dissidents from Colombia's former FARC rebels who announced a return to arms.

The State Department said it would offer $10 million for information leading to the arrest and conviction of either Ivan Marquez or Jesus Santrich.

Colombia in 2016 reached a peace agreement to end decades of fighting with the leftist guerrillas that left nine million people dead, missing or displaced.

But Marquez, who was FARC's number two and chief negotiator, said in August that he was taking up arms and joined fugitive colleague Jesus Santrich.

Secretary of State Mike Pompeo in a statement accused the pair of involvement in drug trafficking and renewed allegations that they are supported by Venezuela's leftist leader Nicolas Maduro, whom Washington is trying to overthrow.

FARC former senior commander Ivan Marquez (center) and fugitive rebel colleague Jesus Santrich(wearing sunglasses) announce a return to arms in an August 2019 YouTube video
FARC former senior commander Ivan Marquez (center) and fugitive rebel colleague Jesus Santrich(wearing sunglasses) announce a return to arms in an August 2019 YouTube video AFP / -

Timothy Shea, head of the Drug Enforcement Administration, said that the FARC holdouts had partnered with "Venezuelan elites" and profited off selling narcotics.

"DEA and our partners are committed to dismantling narco-terrorist organizations such as the FARC, and the corrupt political regimes that support them," Shea said.

Santrich went underground last year after the United States sought his extradition and Marquez already faced a $5 million US bounty, which was hiked Thursday.

While most FARC rebels disarmed under the deal, Colombian authorities say that around 2,300 dissidents remain.

On Wednesday, the Colombian army said that six of its soldiers died in a clash with breakaway rebels.