Kuala Lumpur, Malaysia - Dressed as a migrant worker seeking greener pastures, Indonesian Ali Fauzi crossed into Malaysia's eastern state of Sabah on a fishing boat, dodging maritime patrols with ease under the cover of darkness.
Unknown to his fellow passengers, Fauzi was a member of an al-Qaeda-affiliated group on his way to the southern Philippines to procure guns, explosives and detonators.
"It is very easy to enter Sabah, as the borders are porous. You don't need a passport and I certainly don't carry one," Fauzi told Al Jazeera in a telephone interview from Lamongan, East Java, Indonesia.
Fauzi's easy passage in and out of Sabah between 1994 and 2005 underscores the porous nature of its 1,400km eastern coastline - a vulnerability exploited on February 9 by 200 armed militiamen from the southern Philippines.
The invaders were followers of the self-proclaimed Sultan of Sulu, Jamalul Kiram III, and came to stake an ancient ownership claim to Sabah, located on the northeastern tip of Borneo island.
"Our coastline has always been porous. It is very easy for people from the southern Philippines to come in and out of Sabah. It's about one to two hours away by speedboat," said one Sabah resident who asked not to be named.
Sulu is a grouping of islands that lie between Sabah and the Philippines' Mindanao island.
For centuries, the Sulu Sultanate was an Islamic state that ruled the southern Philippines and parts of what is now Malaysia's Sabah state.
The small force which landed in early February engaged in a three-week stand-off with Malaysia's security forces, despite pleas from both the Malaysian and the Filipino governments to leave.
The situation escalated after the invaders reportedly tortured and mutilated six Malaysian police officers, allegedly ambushing them in a village in Sabah's coastal town of Semporna on March 2.
Two of the six officers were beheaded, a senior police source involved in the Sabah operations told Al Jazeera. The head of a third was left hanging by the skin of his neck.
The killings triggered an air and ground assault by Malaysian security forces to counter the Sulu Sultan's followers.
At least sixty-three Filipino fighters and ten members of Malaysia's security forces have been killed in the operation, according to official figures.
Security operations in Sabah are still ongoing, aimed at flushing out the remaining rebels. They have reportedly infiltrated both the city of Lahad Datu and the town of Kunak.
Fauzi, a 42-year-old Indonesian, knows the town of Kunak well. He frequently stayed there en-route to the Philippines' island of Mindanao island on his gun-running missions.
During his stopovers there, he would borrow the identity card of a Malaysian friend to present to the police on the few occasions he was stopped for identity checks.
"The policeman looked at the ID card and then waved me on. The ID card does not have my name or photo. But in the dark of the night, they never look at the photo to check whether it matched my face," said Fauzi.
Another tactic he employed to avoid detection was to wear a turban and to dress up in the robes traditionally worn by devout religious scholars in the area.
"No one ever stopped me when I was dressed like that," Fauzi told Al Jazeera. "I am seen as a good person."
He denied paying police to turn a blind eye to his smuggling.
"Malaysian cops don't want to be bribed," said Fauzi, adding that he had never been caught.
Fauzi was no ordinary smuggler. He was a former member of Jemaah Islamiyah (JI), the al-Qaeda-linked network behind several hotel bombings in Indonesia.
He is also the younger brother of the 2002 Bali bombers, Mukhlas and Amrozi, who were executed in 2008 for their role in the deaths of 202 people. Fauzi, according to security analysts, was not involved in the attack. Indonesian authorities have never brought charges against him.
Several senior JI members involved in the Bali bombings used this route between Indonesia, Sabah and the Philippines to evade Indonesian authorities after the attack.
The Philippines' Mindanao island, according to Fauzi, was - and still is - awash with weapons easily and readily available on the black market.
He would buy and smuggle between ten and fifteen M-16 assault rifles per trip, working alongside three or four men.
"We packed the guns into large backpacks and travelled on fishing boats or petrol tankers heading for Indonesia from the Philippines," said Fauzi. "No one ever checked our bags."
The weapons were for his comrades fighting Christians in eastern Indonesia's Ambon city in the Maluku islands, and in Poso city in Central Sulawesi. More than 12,000 people were killed in the fighting there between 1999 and 2002.
He told Al Jazeera that he left JI in 1999, as he disagreed with the organisation's response to the Maluku and Poso conflict.
Fauzi also fought with the Moro Islamic National Front (MILF), the southern Philippines' separatist group, for more than six years, from 1994 to 1997 and again between 2002 and 2006.
As such, he is familiar with the armed groups involved in Sabah's conflict. They are battle-hardened and highly-experienced in jungle warfare, he said.
"Many of the armed men in Sabah are from MILF, MNLF (Moro National Liberation Front) and Abu Sayaf," said Fauzi.
"Some of them have little education. If and when their sultan asks them to fight, they will follow his order unquestioningly.
"I believe they have been smuggling weapons into Sabah for the past two or three years and have hid them there, waiting for the right moment to strike."
A senior police source told Al Jazeera the weapons were smuggled in over a period of weeks, not years.
Fauzi laid down arms after his brothers' execution and is now a religious teacher. His story provides an insight into how a combination of porous borders, human traffickers and illegal boat operators enable armed groups to move easily between borders, undetected by authorities.
Like shadows in the night, they are able to smuggle arms, explosive materials and personnel for their various purposes.
In an effort to tighten security, Prime Minister Najib Razak last week announced the establishment of an Eastern Sabah Security Command (Esscom) to safeguard Sabah's coastline.
Indonesia’s National Counter-Terrorism Agency (BNPT) confirmed Fauzi’s account of the easy access from Indonesia to southern Philippines via Sabah.
“What he (Ali Fauzi) said is correct,” said Ansyaad Mbai, charman of BNPT.
“Up until today, the route from Kalimantan, Sabah to the southern Philippines is still the favourite route (for fighters), I don’t know why. This is the same route the militants use to escape from Indonesian security forces to southern Philippines,” adds Ansyaad.
The long coastline and land borders make it difficult for the Indonesian, Malaysian and Filipino governments to secure completely, according to Ansyaad.
Esscom will be given troops, and more police stations will be set up to provide greater surveillance and more security officers.
“Malaysia has enjoyed a long period of peace and stability, but the Lahad Datu incursion has been a stark reminder that external threats remain,” a Malaysian government spokesman said in a statement to Al Jazeera.
“The eastern seaboard of Sabah is almost 1,500 km long and it is critical that we ensure security along this coastline. That is why we have put in place new measures, including the special security area, to increase surveillance and monitoring and prevent illegal entry into Malaysia through Sabah,” said the statement.
Body count 'still low'
Residents of large swathes of the areas affected by the recent violence have cultural and family ties with the southern Philippines.
"That is why the cops often close one eye when illegal immigrants come in, as they themselves have family ties with southern Philippines," said one Sabah resident.
The current conflict is complicated by the illegal immigration of Filipinos to Sabah, the population of which has quadrupled since the early 1970s. The government of the Philippines has estimated the Filipino population in Sabah to have reached 800,000.
Sabah was also rocked in recent weeks by allegations that illegal immigrants were given identity cards by past leaders of the ruling United Malays National Organisation (UMNO) in exchange for their votes.
Both the conflict and these latest revelations are unfolding ahead of a general election, expected to be called within weeks.
Sabah is a crucial state for Malaysia's political parties, as it holds 25 seats, the third largest bloc in the 222-seat parliament.
According to political scientist Professor James Chin, the Sabah crisis will impact only on Peninsular Malaysia, and not Sabah itself.
"Najib (Prime Minister Najib Razak) will play the nationalist card, where he will be seen as a strongman defending the country, especially amongst the Malay community," said Chin, a senior fellow at the Institute of Southeast Asian Studies in Singapore.
"The impact will not be felt in Sabah, as nationalism is a very fluid thing - just like their borders. One third of their population is from the Philippines."
Securing Sabah's coastline will be a challenge, despite the new security command, as the Malaysian navy lacks capacity, said Chin.
Describing the ongoing security operations as "a mopping-up operation", Chin expressed concerns over possible revenge attacks by members of the Sulu army.
"This will very much depends on the body count of their people," he said. "Right now, the body count is still quite low."
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