The Scout Rangers Class 146-02 under the operational control of the Eight Infantry Division storm troopers uncovered the extensive tunnel complex with complete facilities and utilities when a local resident tipped them off on the presence of the NPA camp.
The army, however, said the rebels managed to leave the area before the arrival of the soldiers.
"There was an observation post that provides sufficient warning to them when somebody is coming," Lt. Col. Romeo Velasco, the Assistant Chief of Staff for civil military operations, said.
Situated in a thickly vegetated area in a mountain slope, the underground base, about 100 meters away from the trail commonly used by the farmers, has two bedrooms, armory room with a warning device and can accommodate about 15 persons.
"It (the tunnel) was constructed similar to a house with complete emplacement of the facilities (which are) needed most," Velasco said. He added that the tunnel has one main entrance and five exits strategically located in every corner of the base camp.
The military recovered inside the underground base one caliber .22 revolver, complete set of optometric trial lenses, one voltage transformer, a cassette recorder with three tapes, extension wire, 12 diskettes, three compact disc, a cellphone charger, local and national newspapers, medical manuals and voluminous subversive documents of high intelligence value.
Velasco said that it is possible that some residents of the neighborhood might have knowned its construction due to the extensive use of bamboos which do not grow in the area.
"Due to fear of the enemy’s reprisals, they had remained silent until they became aware of its dangers and decided to tip off the soldiers," Velasco surmised.