One man was shot and four Malaysians kidnapped after Abu Sayyaf attacked a tug on Friday.
The incident on the border between Malaysia and the Philippines was the group's third hit in a vessel in quick succession.
The injured man and five others from the 245-gt tug Henry (built 2003) were safely taken to Malaysia after the drama.
Reports this morning from The Star newspaper claim the Abu Sayyaf operatives are seeking a ransom and have posted a picture of the four men on Facebook to influence the family in the negotiations.
