A man reputed to be Colombia's oldest paramilitary fighter has laid down his weapons at a ceremony in the north.
Ramon Isaza (L) was a rancher before founding his faction
Ramon Isaza, thought to be at least 65 and accused of rights abuses and drug smuggling, demobilised along with nearly 1,000 paramilitaries.
The disarmament of Mr Isaza and his faction - the Magdalena Medio Bloc - brings the number of demobilised paramilitaries to more than 22,000.
Many paramilitary groups were founded in the 80s to fight Marxist guerrillas.
During the ceremony in the town of Puerto Triunfo, in Antioquia province, the militias handed over hundreds of weapons in the presence of Colombian officials and international observers.
Known as "the Old Guy", Mr Isaza was a rancher before founding his faction in the late 1970s to combat Marxist rebels.
He said he recruited fellow farmers armed with guns to ambush rebels who had been stealing their chickens, pigs and cows, and were threatening to kill him.
His Magdalena Medio Bloc belongs to Colombia's biggest paramilitary group, the United Self-Defence Forces of Colombia (AUC).
Under the controversial peace process, those who have committed crimes and agree to disarm face reduced prison terms.
Most of the rank-and-file paramilitaries are expected to be pardoned and can be eligible for job-training programmes and a monthly government stipend for two years.
Colombian President Alvaro Uribe has also announced that thousands of them could join a civil police force that already has more than 500 men.
Human rights groups are concerned that fighters who have committed atrocities will go unpunished.