The tugboat M/T Sintel Marine 88, with a crew of 10, was towing a barge, the Labroy179, carrying over 17,000 tons of coal from Indonesia to Cebu when it was intercepted off Tamuk island.
The island is six kilometers southwest of Basilan, the Abu Sayyafs stronghold. The area is also infested with pirates.
Two Philippine Navy patrol boats were dispatched to look for the barge and tugboat, said Coast Guard Capt. Damian Carlos, after the vessels were reported missing by the barges Indonesian owner late Monday.
The Philippine Navy patrol boat BRP Sultan Kuda-rat found the vessels and their remaining crewmen off Tamuk early yesterday morning.
Maj. Gen. Ernesto Carolina, chief of the militarys Southern Command, said the tugboat and barge and the six remaining Indonesian crewmen were brought to Zamboanga City.
The six crewmen told the military at least eight gunmen on a motorboat had boarded the tugboat and taken the captain, the chief officer, chief engineer and chief mate hostage.
They also took off with some communications equipment and disabled the boats radio transceiver. The group then sped off toward Sulu, an Abu Sayyaf stronghold.
However, the crewmen managed to fix the radio and call their company in Singapore for help.
Defense officials have initially identified the victims as captain Muntu Jacobus Winowatan, chief officer Julkipli, chief mate Ferdinand Joel, and chief engineer Pieter Lerrech.
The six remaining crewmen were identified as Muhamad Kadapit Djabir, Jamiul Alim, Amir Hamzah Terilengkan, Heri Juhaeri, Arik Sutarto, and Amal Riki.
However, the Indonesian embassy said it would not release the names of the victims until further verification from authorities and the other crew members.
Carlos Digamo, representative of World Mariners Inc. which contracted the tugboat, said the coal supplier, Singapore-based Noble Energy, had concluded that the kidnappers were members of the Abu Sayyaf.
Digamo said the tugboats captain was new on the job and apparently chose the shortest route to Cebu.
Wearing military fatigues, the gunmen approached the barge and fired warning shots in the air and forced the victims into their boat, said Sthillainathan Thillai, a manager for the vessels Singaporean owner, citing accounts by crew members left behind.
"Nobody was injured," Thillai said. "They (the kidnappers) were not wearing masks."
Joey Mirasol, World Mariners operations manager, said they have yet to receive any demand from the kidnappers.
He said the barge and tugboat were victimized five or six years ago by gunmen at sea. However, the attackers took only food, radio equipment and fuel. No one was abducted.
Military intelligence sources in the South also blamed the Abu Sayyaf, who are known for carrying seaborne raids and have donned military uniforms in the past to conceal their identity.
"We cannot categorically say if this was the Abu Sayyaf or just ordinary bandits," said Carolina, whose troops have been hunting down the Abu Sayyaf.
He added the attack could have been mounted to "relieve the pressure" on their fellow members under intensified military assault in Zamboanga del Norte.
The Abu Sayyaf, a group linked to the al-Qaeda network of fugitive Saudi terrorist mastermind Osama bin Laden, lost its hostages when Philippine troops mounted a rescue attempt on June 7.
American captive Gracia Burnham was recovered, but her husband Martin and a Filipina nurse, Edibora Yap, were killed in the raid.
With no hostages to worry about, the Philippine military intensified its efforts to crush the Abu Sayyaf.
Military and police officials earlier warned that the bandits could seize more hostages to use as shields to ward off the military offensive.
Carolina said troops in Sulu and Basilan are on the lookout for the kidnappers. Two Philippine Air Force MG-520 attack helicopters were sent to Sulu to help the Coast Guard in search of the kidnappers, he added.
At Malacañang, acting Press Secretary Silvestre Afable said President Arroyo had been informed of the abduction. Describing the situation as "unfortunate," Afable expressed confidence of an "early solution to this problem."
However, the abduction has put in question the capability of the Philippine Navy to prevent the Abu Sayyaf from repeatedly carrying out seaborne raids.
Carolina admitted they "cannot guarantee" that they can stop the bandits from striking again because they dont have enough forces to patrol the souths vast coastline.
A thousand US troops are deployed in the south, helping local forces in the campaign against the bandits, but they are barred from taking part in combat except in self-defense. With Paolo Romero, Nestor Etolle, Jose Aravilla, Pia Lee-Brago, Marichu Villanueva, AFP