National Police Chief Gen. Oscar Naranjo holds a gun seized from Pedro Guerrero, also known as "The Knife."

A right-wing paramilitary leader in Colombia was killed in a police operation on Christmas Day, Colombian President Juan Manuel Santos confirmed Wednesday.

Pedro Guerrero, also known as "The Knife," was a ruthless killer and a major drug trafficker, the president said.

On December 24, national police forces dropped in from helicopters to raid a building where Guerrero was thought to be. The operation carried on into the early morning, the president said, and Guerrero -- the leader of the Popular Revolutionary Anti-terrorist Army of Colombia, or ERPAC by its Spanish initials -- managed to escape the building.

However, Santos said, police were ready with a perimeter around the area. His body was found shortly afterwards.

Two police were also killed in the confrontation.

ERPAC is known for its large cocaine production and distribution activities. The group emerged from the fighting between leftist rebels and right-wing paramilitary groups.

"This individual caused much damage to our country. That's why this strike is so important," Santos said, calling Guerrero "the killer of killers."

He is believed to be responsible for more than 2,000 killings in southern Colombia and earned the nickname "The Knife" for his alleged penchant for slashing throats.

On Guerrero's body, they found a handgun plated with gold and diamonds, and a knife was in his hand, Santos said.

A reward will be paid to "several" people who helped authorities find Guerrero, the president said.

"This is a warning to all the other criminals: You will fall," Santos said.

The operation is evidence that the government goes after not only the left-wing rebels but also the paramilitary criminals, the president said.