The arrest and interrogation of Fathur Rohman Al-Ghozi, the alleged Indonesian munitions expert and member of Malaysia-based Jemaah Islamiah, has yielded a number of leads that are likely to keep Manila's intelligence agencies busy for months to come.

None of them are about the alleged link between Osama bin Laden's al-Qaeda network and the Abu Sayyaf extremists who are holding an American missionary couple and a Filipina nurse hostage.

This could prove embarrassing to the Philippine and the US - 660 US soldiers arrive in the southern island of Mindanao to open what US President George W. Bush called the US' second front against international terrorism.

The known links between al-Qaeda and Abu Sayyaf go back to the early 1990s, when Mohammad Jafal Khalifa, bin Laden's brother-in-law, was in Mindanao as head of an Islamic charity organisation.

Apart from setting up clinics, running orphanages and sending scholars to the Middle East, police allege Mr Khalifa also helped organise the Abu Sayyaf to rid the predominantly Muslim provinces in the south of Christian influence.

From all indications, the relationship between al-Qaeda and Abu Sayyaf ended in the mid-1990s when Mr Khalifa left the Philippines and was blacklisted after being linked to people convicted for bombing the World Trace Centre in 1993.

The Abu Sayyaf gradually turned to kidnapping for ransom, especially after the death of its charismatic founder in 1995.

Mr Al-Ghozi, arrested last month in Manila, has provided information suggesting personal and organisational ties between Jemaah Islamiah and the Moro Islamic Liberation Front. He has also given leads on the illegal trade in explosives substances and the lax enforcement of rules by the police, particularly the firearms and explosives regulatory units. But he had nothing to say about the Abu Sayyaf.

"It exposes the shallow bases for the joint US-Philippine military exercises against the Abu Sayyaf," says Glenda Gloria, co-author of a book on the Muslim rebellion in Mindanao, on the apparent lack of evidence linking Abu Sayyaf to international terrorism.

She agrees the government needs to move decisively against the Abu Sayyaf but doubts if large-scale military operations, even with additional support from US special forces, will do the job.

"They can readily dissolve into the community or remain inactive while military operations are going on," she points out.

Despite the weak evidence of direct links between al-Qaeda and the Abu Sayyaf, everything is working according to plan for both the Philippines and the US.

US troops have established a hold in the southern Philippines, and President Gloria Macapagal Arroyo has received promises of more US military assistance. At least $100m is expected this year and next, compared twith almost none since the US bases were closed in 1992.

Still, fears abound that US military presence may simply fan the flames of resentment and rebellion among the Muslim minority in this largely Christian southeast Asian nation.

Julkipli Wadi, a professor of Islamic Studies at the state university, said the Philippine military has a poor record of distinguishing between rebels and civilians among the Muslim population, and the joint military exercises may very well increase civilian casualties.

He noted that many of the rebel casualties being reported by the military are actually civilians caught in the cross-fire.