(CNN) -- The No. 2 leader in a Marxist guerrilla group that has been at war with the Colombian government since the 1960s has been killed in a military raid, President Juan Manuel Santos said Thursday.

Victor Julio Suarez Rojas, also known as Jorge Briceno Suarez and by his nom de guerre Mono Jojoy, was the military leader for the Revolutionary Armed Forces of Colombia, commonly called the FARC.

Firefights between the military and the FARC continued into Thursday night, Defense Minister Rodrigo Rivera told CNN en Español.

Rivera called the site where the military raid took place "the mother of all FARC camps." The camp was 300 meters (1,000 feet) long and had a bunker reinforced with concrete in the middle, he said. There were 13 satellite camps around the main camp, he said.

So far, authorities recovered 20 computers, 68 USB drives and three external hard drives that could hold valuable intelligence for authorities, Rivera said.

At the camp, troops also found four tons of fresh food.

Santos called the rebel leader's death a "historic" event.

"This is the biggest blow the FARC has suffered in its history," Santos said from New York, where he is participating in meetings of the United Nations General Assembly.

"To the rest of the FARC, we are going after them," Santos said. "We are not going to rest."

Santos said that some 20 others were killed in the raid, but later Rivera clarified that by saying as of Thursday night, only seven bodies had been recovered.

The army reported that another top rebel leader, Henry Castellanos, alias Romana, was also killed but later retracted the statement. The defense ministry will wait until all of the bodies are examined before confirming whether any other leaders were killed.

"The nightmare that he wanted to impose on Colombia is ended," Santos said in a later speech. Suarez was a symbol of cruelty and inhumanity, he said.

Details of the intelligence that led to the operation was not disclosed, but Rivera said that there would be a reward handed out in connection with the death of Suarez.

The guerrilla leader was killed near the town of Macarena, in the southwestern Colombia state of Meta.

The final operation against Suarez started early Wednesday, Rivera said, adding that officials had spent two sleepless nights awaiting the results.

Five Colombian soldiers were wounded in the operation,which included heavy airstrikes, Rivera said at a news conference from Bogota, the nation's capital.

The guerrilla leader's death was the FARC's second major setback in the past few days.

An airstrike over the weekend killed a high-ranking rebel commander who was wanted in the United States, police said.

Sixto Antonio Cabana Guillen was among the more than two dozen guerrillas killed in a Colombian air force bombing operation Sunday, the National Police said Monday.

The U.S. State Department had been offering a reward of up to $2.5 million for information leading to his arrest or conviction.

Cabana, as a top member of the FARC, helped set policies directing and controlling the production and distribution of hundreds of tons of cocaine to the United States and the world, according to a statement on the State Department's website.

Speaking at Thursday's news conference in Bogota, Rivera urged FARC leader Guillermo Leon Saenz, known as Alfonso Cano, to surrender.

"We guarantee your life," Rivera said. "We guarantee just treatment."

Regardless, Rivera vowed, the war against the FARC will continue.

"They have robbed us of nearly 50 years as a nation," he said. "We are going to end the narco-terrorist FARC nightmare."

Suarez, who was believed to be 47, joined the FARC as a teenager and rose through the ranks to become commander of one of the rebels' seven fighting divisions. He became a top commander in the early 1990s, when he was appointed as one of the FARC's seven-member general secretariat.

He eventually became the FARC's military commander in chief.

Although he was considered the No. 2 person in the rebel group, Suarez had much more military experience and time served in the FARC than its leader, Cano, who was appointed to the general secretariat as the result of a deal with the Colombian communist party.

In recent years, Suarez had been in charge of holding significant prisoners and kidnap victims in jungle camps. He also was in direct command of units responsible for the deaths of three Americans in 1999. He was under indictment in the United States for those deaths as well as drug-trafficking charges.

Suarez also was the first FARC commander to order in the late 1980s or early 1990s that the rebels collect a tax from peasant farmers on coca plant cultivation. That, analysts say, marked the start of the FARC's wholesale involvement in drug trafficking.

CNN's Karl Penhaul contributed to this report.