ZAMBOANGA:  A Japanese man who went missing on a remote southern Philippine island may have been kidnapped, authorities said Saturday.

The man, named by local police as Amer Katayama Mamaito, was last seen on Pangutaran island in the Sulu archipelago, a stronghold of Abu Sayyaf Islamic militants who have kidnapped foreign tourists and missionaries in the past.

Police and military officials are investigating unverified reports that he left the island with about 10 gunmen early Friday, said regional military commander Lieutenant-General Ben Dolorfino.

"Our initial information is that he is engaged in treasure hunting and has been living there for the past five years," he said.

Police investigators have been sent to the island to gather more information about the missing man, said regional military spokeswoman Army First Lieutenant Steffani Cacho.

Authorities are treating the case as a potential abduction, said Chief Superintendent Bienvenido Latag, the regional police chief.

"We will activate the crisis management committee and form a task force to get the background of the victim and also to monitor the incident," he said.

The Abu Sayyaf is a small group of militants on the US government`s list of foreign terrorist organisations that is well known for staging kidnappings for ransom in the southern Philippines.

The Sulu group is regarded as one of the Abu Sayyaf`s strongholds and is extremely dangerous for foreigners.

They abducted three Red Cross workers including two Europeans there last year. All three were freed unharmed several months later amid speculation that ransom was paid.

In one of their most notorious acts, the Abu Sayyaf beheaded one of three American hostages they seized from a resort on Palawan island in 2001. One of the other hostages was killed during a rescue attempt a year later.

The group is also blamed for the 2004 bombing of a passenger ferry that killed over 100 people in Manila Bay.

BDST: 0930 HRS, 17 July 2010