Peru's government say its campaign against the Maoist guerrilla group Sendero Luminoso is proving successful with a high-level leader and two other members killed in a firefight.

Peruvian President Ollanta Humala said Monday Sendero's second in command, Alejandro Borda Casafranca, known as "Comrade Alipio," died with two other Senderista guerrillas in a battle with government forces Sunday night in Llochegua, a jungle area in the Apurimac, Ene and Mantaro river valley where the group provides protection to cocaine traffickers.

El Commercio newspaper reported Tuesday that Humala told reporters following the reported killing of the trio that weapons were recovered and other materials were being analyzed.

The president said the operation was the result of "patient intelligence work" by a special joint brigade of police and the armed forces.

"We have struck an irreversible blow to the Senderista remnants," Humala said.

Humala predicted that following the assault the remaining Sendero Luminoso guerrillas would experience a leadership crisis.

When Peru returned to civilian rule in 1980 with the re-election of Fernando Belaunde as president, Sendero Luminoso began a guerrilla campaign against not only the Peruvian government, but Peruvian society in general, seeking to overthrow its capitalist nature. An outgrowth of the Communist Party of Peru, Sendero Luminoso sought to reorder Peruvian society along the lines of China under Mao Zedong, sweeping away colonial elements in order to build what the group said would be a more equitable society founded on its perceptions of the basis of pre-Colombian Incan "socialist" antecedents.

Sendero Luminoso's impact on the country began to falter in 1990, when Independent center-right politician Alberto Fujimori was elected president on an anti-corruption platform. Fujimori made it a high priority of his administration to crush Sendero Luminoso by any means necessary. In 1992, Fujimori suspended Peru's Constitution with the backing of the army and his anti-guerrilla campaign scored its great victory later that year when special forces captured Sendero Luminoso's leader and ideologue "Chairman Gonzalo," Abimael Guzman, who was sentenced to life imprisonment. Two years later, 6,000 Sendero Luminoso guerrillas surrendered to the authorities.

Peru's Truth and Reconciliation Commission said roughly 70,000 people, primarily peasants, were killed or "disappeared" in the Peruvian government's campaign against Sendero Luminoso between 1980 and 2000, and forensic teams are still exhuming mass graves in mountain villages in the Andes.

While Fujimori's rule ended with his conviction for human rights violations, embezzlement and other charges, his brutal anti-guerrilla campaign and Guzman's capture diminished Sendero Luminoso's influence. In the two decades since Guzman's capture and sentencing, Sendero Luminoso has become a shadow of its former self, no longer able to mount massive operations. Its members have retreated into remote areas, where their major source of revenue is now apparently providing protection to drug traffickers. In December 2011, Sendero leader Florindo Eleuterio Flores Hala, "Comrade Artemio," admitted to reporters the organization had been defeated, and said its remaining guerrillas were ready to negotiate with the government.

Authorities worry about Sendero Luminoso's continued presence in the Apurimac-Ene valley as Peru's drug problem escalates, with the country close to overtaking Colombia as the top producer of cocaine.