Three factory workers were abducted in the southern Philippines on Tuesday, a day after authorities found the severed head of a previous kidnap victim, officials said.

Armed men in military-style uniforms seized three workers from the Hitech Wood Craft Corp. in Maluso town on Basilan island before dawn, said provincial police chief Abubakar Tulawie.

The identity and motive of the kidnappers in Basilan are still unknown but provincial Vice Governor Al Rasheed Sakalahul said: "Money could be the motive for this. Ransom was probably the reason here."

It is the latest kidnapping crisis to hit the country and comes just after the severed head of a school principal abducted by suspected Islamist militants was dumped at a petrol station on nearby Jolo island on Monday.

Kidnappers on the southern island of Mindanao, the hotbed of a decades-old Muslim separatist rebellion, are also holding 79-year-old Irish Roman Catholic priest Michael Sinnott.