In a press conference Wednesday, Magdamit said the hostages were abandoned by the tribesmen on Sitio Baleta, Barangay La Purisima in Prosperidad town at 6 a.m. Wednesday.
Released were Department of Education district supervisor Narciso Oliveros, principal Apolono Alibangbang, property custodian Joel Sausa, teachers Manuel Mordano, Felipina Quitoy, Allan Gallano, Mary Jane Bedrijo, Arnold Quitoy, Pido Dolorito, Girlie Monticalbo, Marical Lagnazon, and Diosdado and Shen-shen Cabagtac.
The mayor clarified the 13th captive, Diosdado, was earlier freed by the tribesmen but returned to offer himself as hostage in exchange for his son Shen-shen.
He said the hostages were freed after Jobert “Ondo” Perez, a jailed tribal leader who is their relative, convinced them to release the victims.
He also said the assurance of fair treatment to the hostage-takers may have contributed to the peaceful end of the hostage crisis.
"This is a result of a dialogue… They clarified their demand was for them to be treated fairly… We believe these assurances along with the mounting pressure from the troops on the ground forced the abductors to leave their hostages," he said.
All of the freed hostages were "in good physical condition aside from minor insect bites" and were subjected to medical exams and debriefing upon their release, Magdamit said.
The mayor, however, said: "Basta pinakawalan na lang yung mga hostages. Hindi namin alam nasaan yung hostage-takers."
Department of Interior and Local Government Secretary Jesse Robredo affirmed the report, saying government troops are now on hot pursuit operations for hostage-takers, who are reportedly minors.
Robredo added the hostage-takers will be facing criminal charges.
He also said officials met Tuesday with Ondo Perez who asked to be treated fairly in his case.
Robredo said officials assured Perez that his case will be treated fairly.
However, he said: "This is not a fight between him and government. This is just a fight between two families. He cannot demand to be absolved of his cases."
Meanwhile, Malacañang was delighted by the peaceful ending of the Agusan del Sur hostage crisis.
“We are very pleased about the peaceful resolution of the hostage taking at Agusan del Sur,” Presidential Development and Strategic Planning Secretary Ricky Carandang said.
"Throughout the ordeal, the safety of the victims was President Aquino’s paramount concern and he is happy to know that they are safe and free,” added Carandang.
He thanked officials who contributed to the peaceful resolution of the crisis, particularly Agusan del Sur Governor Adolf Edward Plaza, Mayor Albin Magdamit, National Police Chief Raul Bacalzo, and provincial social welfare officer Josefina Bajade.
The Palace also lauded the local crisis management committee composed of the local police, the Armed Forces and the National Commission for Indigenous Peoples.
He also noted the efforts of Interior Secretary Jesse Robredo, who flew to Agusan on the instructions of the President to personally oversee the negotiations.
“The cooperation of the local government leaders and the community, the National Government, and the media was instrumental in obtaining the release of the hostages,” Carandang said.
In a separate interview, Presidential Communications Operations Secretary Sonny Coloma said authorities will tighten security in areas prone to kidnapping incident.
He said this directive came from President Benigno Aquino III following the involvement of innocent children in the kidnapping.
He stressed the need for the government to intensify campaign against kidnapping, especially in Mindanao.
On Friday, 13 school officials and two students, who came from graduation ceremonies in three schools in Prosperidad town, were snatched at gunpoint and taken to a forested area of the town.
Armed tribesmen earlier freed a 12-year-old boy and Agusan del Sur Division Superintendent Hipolito Lastimado and Diosdado Cabantac.
Earlier, police identified the five hostage-takers as Ken-Ken Perez, Rejoy Brital, Rolando Perez, Alejandro Navarro Brital, and Allan Perez.
The hostage-takers have demanded the release of tribal leader Ondo Perez, who was jailed with three other tribesmen for taking 79 people hostage in 2009 over a long-running clan feud.