Kidnapping comes as the government is trying to capture scores of militiamen suspected of being involved in last month's massacre of more than 50 people in Maguindinao province.
In the southern Philippines government negotiators continue talks with clansmen holding 48 hostages. The leader of the group demands that murder charges against them be dropped.
In the southern Philippines 15 members of a clan freed nine hostages Friday. They were among 75 people seized Thursday from a school in Agusan del Sur province. The kidnappers freed 18 of the hostages shortly after taking them.
Police say the gang leaders are wanted on murder charges, but the hostage-takers deny the allegation.
Presidential Press Secretary Cerge Remonde says the government hopes to resolve the kidnapping peacefully.
"I was assured by our military commanders that they are ready to move in anytime when the local crisis management committee will give them a signal, but of course right now the local management committee is exhausting all possible peaceful negotiations," said Remonde.
Joebert Perez, the leader of the gang, says the charges against him are fabricated and blames a rival clan, the Tubays, for the murders of six of his siblings. He demands that police disarm the other clan before he will free the remaining hostages.
Government negotiators say they are attempting to disarm both clans.
Police say the hostage-takers are former militiamen who have turned to banditry and extortion, targeting mining and logging companies in the area. For decades, the Philippines government has armed civilian volunteers as a backup security force in areas with communist or Muslim insurgencies.
Remonde says the military is making progress in disarming these militias.
"As of December 10, a total of 1,013 firearms, along with 591,000 rounds of ammunition and C-4 explosives have been confiscated or have been surrendered to authorities," said Remonde.
The kidnapping Thursday comes as the government is trying to capture scores of militiamen suspected of being involved in last month's massacre of more than 50 people in Maguindinao province. They were gunned down to prevent one of the victims from registering her husband as a candidate for provincial governor.
The southern Philippines has long had a violent history. For decades Muslim insurgents have fought for a separate homeland in the south. Several groups that say they are fighting for that homeland have targeted civilians - kidnapping and often killing tourists, farmers, business people and others.