BOGOTA, Colombia (AP) - Soldiers chasing a rebel band of kidnappers in the mountains near the capital stumbled upon an army of hundreds of guerrillas, opening a fierce three-day battle that killed at least 20 people by Monday.
About 400 rebels were caught up in the unusually heavy fighting, leading to speculation that the army had come upon the headquarters of the Revolutionary Armed Forces of Colombia, known by its Spanish initials as FARC.
Guerrillas rarely gather in such large numbers unless they are planning a major attack. About 400 overran a military base in the southern jungle on Aug. 30, killing 27 soldiers and capturing 60.
Security experts have speculated that the rebel leadership, a seven-man council called the Secretariat, is based in the area, which would allow radio coordination of rebel forces around the country.
The government has offered a $1 million reward for rebel commander Manuel Marulanda, a man in his 60s. Nicknamed "Sureshot", he comes from a peasant family and has been a guerrilla since his youth.
The fighting began when an army patrol pursuing a band of kidnappers stumbled on the rebel force late Saturday near San Juanito, a village 30 miles southeast of the capital.
Military helicopters ferrying fresh units were unable to land at first because of intense fire. The area in Meta state is hard to reach, with mountains up to 13,000 feet high.
The military has lost contact with one army unit of 40 men in mist-shrouded forest where the combat is most intense, Gen. Jorge Enrique Mora, commander of the army's fifth division, told RCN radio.
Red Cross workers recovered 20 bodies and removed eight wounded, a Red Cross spokeswoman said in the nearby city of Villavicencio. She spoke on condition of anonymity, and said she did not know whether the casualties were rebels, soldiers or both.
Citing a top government official, Bogota's El Tiempo newspaper said at least 18 soldiers were killed.
"We're very worried", Gen. Manuel Bonett, the army chief, said at a news conference.
President Ernesto Samper was stalwart in an appearance on national television Monday, saying the rebels had suffered "considerable casualties". "We're not going to withdraw from the area", Samper said.
The leftist insurgency is Colombia's oldest and largest, with up to 10,000 fighters. Another group, the National Liberation Army, also has been fighting since the 1960s.
In the past few years, the FARC has reinforced units around the capital and formed new ones. It controls many rural areas and often raids small towns, but has yet to threaten the government seriously.