The Indonesia-based JI is believed to be a terrorist organization responsible for the bombing of two nightclubs in the island resort of Bali, Indonesia last year.
Highly placed sources told The STAR Filipino and Indonesian intelligence officials have been exchanging information, including photo profiles of at least 300 JI members.
"The joint monitoring was done as it was detected that there has been an unusual movement of the suspected 31 members in the island, that was what alarmed the intelligence community," sources said.
"They seemed to be waiting for something. The escape of Al-Ghozi could have boosted their morale. But that is not what matters to them because they still work under instruction from somebody they believe is within the hierarchy of recognized existing structure."
Meanwhile, reports said seven JI members entered a Muslim community in the boulevard area here early this month before heading for Pantukan town in Compostela Valley province, a known lair of the Moro Islamic Liberation Front (MILF).
"But even if how independent these JI cells operate, still there is a certain level of respect among them that they would only launch bomb attacks with the go-signal of the highest official of the MILF," sources said.
JI members in Sulawesi and other East Indonesian provinces are reportedly able to freely travel to known MILF camps in Central Mindanao to train in bomb making and other terrorist activities.
"The intelligence communities of both countries have been working on them and they have their profiles already," sources said. "They have a clear picture of how they operate independently by cells and even their location."
Many JI members are said to have taken refuge in MILF communities in Maguindanao and the Lanao provinces during a lull in fighting between government troops and secessionist rebels.
They have reportedly spread out and linked up with the Abu Sayyaf in Western Mindanao, particularly in the cities of Zamboanga and Pagadian.
JI cells are also said to be operating in General Santos City and the coastal towns of South Cotabato, where they can sneak in via the sea from islets near the Philippine-Indonesian border.
Sources said Philippine authorities have tightened their watch over Indonesian ships docking regularly at the Sta. Ana Wharf in violation of a border patrol agreement between the two countries.
"If you really follow the border patrol agreement between the two countries, these boats are not supposed to be docking in Davao City but in the town of Tibanban in Davao Oriental, where the border crossing station is located," sources said.
"Let us face it, some of those JI members have passed through the route in entering the country easily."
The STAR chanced upon the Indonesian ship M/L Friendly-04 late Friday at the Sta. Ana Wharf.
The Indonesian vessels M/L Filadelphia and M/L GLoria have also been seen shuttling between Davao City and Indonesia’s Miangas island.
However, Cesar Paquingan, authorized local representative of Friendly’s owner Denny Theowidjaja, said it was legal for the Friendly to dock in Davao City to buy merchandise for sale in Manado, Indonesia.
"We are doing everything to comply with the requirements, including the needed permits for exports and imports," he said.
The STAR found out that the Friendly’s latest trip was the first time its 14 Indonesian crewmen had carried passports after four years of plying the route.
"They only used to have border passes before," said immigration bureau staff Sak Baluan.
But a certain Arifin Makahenggeng, a crewman of the Friendly, has denied that they have been transporting passengers and cargo to Davao City.
"We never carried any passenger nor do we bring in anything," he said. "We only come here to buy and sell them in our place. Do you think we carry explosives? Do you think slippers would explode?"
The Friendly, Filadelphia and GLoria frequent Davao City, one after the other, once every three months.