They are said to have entered via Palawan and Tawi Tawi in southern Philippines.
Esscom will also ensure safe passage for the planned ferry service between Kudat in Sabah and Palawan.
The Philippine Star recently reported a senior counter-terrorism official as confirming that prior to the Islamic State (IS)-linked groups’ siege of Marawi city, a dozen foreign militants – some from the Middle East – had entered the country through Palawan and Tawi-Tawi from Malaysia.
He said government agents are verifying the presence of foreign jihadists in Mindanao as well as in other urban areas, including Metro Manila.
The official did not say which part of Malaysia or Sabah the foreign militants had departed from.
However, Kudat is the closest on the Malaysian mainland to Palawan, with Pulau Banggi, a Malaysian island, situated in between.
“We are aware of the soon-to-be-started ferry service between Kudat and Palawan in the Philippines,” Esscom chief Hazani Ghazal said when contacted by FMT.
“Kudat is inside the Eastern Sabah Security Zone (Esszone). I believe the authorities will create a CIQ (Customs and Immigration Quarantine) post for travellers between the two places.
“We are intensely monitoring movements along our borders with southern Philippines, including our part of the planned Kudat-Palawan ferry route.
“As for the reported entry of foreign militants entering southern Philippines from Malaysia via Palawan and Tawi Tawi, we will find out from our Philippine counterpart whether the report is true.”
The island province of Palawan is about six hours away via the planned ferry service from Kudat.
The Philippine Star also reported that a group of at least 100 foreign fighters, fresh from IS-supervised training in Indonesia, had entered Mindanao in batches, before the Marawi clash ended.
Interestingly, this happened at the same time FMT was reporting last month that a group of at least 120 fighters, possibly including Malaysians and Indonesians, had gathered in central Maguindanao.
Terrorism Research and Analysis Consortium (TRAC) had told FMT it had detected chatter about the group on IS-related communication channels.
The Philippine daily had further reported that some of these militants had gone straight to Mindanao from Indonesia in a bid to reinforce their trapped cohorts in Marawi.
“While a handful of these foreign militants made it to Marawi, most did not because of the tight security the military enforced around the city,” the report said, citing a source.
The presence of these foreign jihadists, the source said, could be the reason why President Rodrigo Duterte kept on saying that the terrorism problem in the country was not over yet despite the defeat of the Maute group.
The Maute group was one of the groups responsible for the Marawi attacks.
“This is now causing us some concern because of the upcoming Christmas celebrations,” the source said.
The daily also cited reports that “all these foreign jihadists – including those who linked up with the Abu Sayyaf bandit group in Sulu, Basilan and Tawi-Tawi – are headed by a young Indonesian terrorist, identified as Abu Mohammad Busrow.
“A separate intelligence brief showed that Busrow, along with a Jordanian terrorist, has a US$1 million bounty on his head and is closely associated with slain Abu Sayyaf leader Isnilon Hapilon, who was said to be the designated IS emir in Southeast Asia.”
Philippine and Malaysian authorities have publicised the names of only some Malaysian militants in Marawi.
However, TRAC told FMT that based on chatter it was monitoring, there were at least 30 Malaysians involved in the siege.
More than 1,100 people, mostly militants, were killed in the clashes between troops and militants who wanted to create a so-called IS caliphate in Marawi.
The operator of the ferry service, which will start before Christmas, said sea marshals will be stationed on its vessel.
The service is expected to boost existing trade between Kudat and Palawan.
Sabah’s tourism set for boost with Kudat-Palawan ferry service