At least six people, including three Filipinos, are being held captive by some 80 members of separatist group Abu Sayyaf, a military official said Monday.

Believed to be still in custody of the Abu Sayyaf are Dutch national Ewold Horn, Filipino-Chinese Yahung Chen, Joshua Bani from Tawi-Tawi, Korean national Nwi Seong Hong, seven-year-old Tausug Emeil Jaid, and retired Philippine Marine Renato Fernadez.

Col. Alan Arrojado, head of the Joint Task Group Sulu, however, refused to confirm or deny that the group of Abu Sayyaf commander Radullan Sahiron is holding a seventh person captive for ransom.

On Sunday, Armed Forces of the Philippines spokesperson B/Gen. Joselito Kakilala said joint operatives of the police and the military have impounded three unregistered double-engine “Junkong” boats in Alicia, Zamboanga Sibugay believed to have been used in the abduction of Naga Mayor Gemma Adana.

Adana was believed to have been kidnapped by the Waning Abdusalam Group, a lost command of the Moro Islamic Liberation Front and delivered to the Abu Sayyaf faction in Sulu.

According to Arrojado, his group has already neutralized 52 Abu Sayyaf bandits in a series of operations in Patikul, Indanan, and Talipao from January to March.

But his troops are exercising caution in pursuing the Abu Sayyaf to avoid causing injury and death to the kidnap victims.

“The bandits are highly mobile with their kidnap victims in tow. Sometimes they converge, sometimes they move in groups every time our pursuing troops pinpoint their location,” Arrojado said.