The Utusan Malaysia, a Malay-language daily, said the cache included a large amount of explosive material and 216 bullets.

The military had deployed divers to search the seabed after the migrants reportedly dumped weapons overboard when they were spotted by the military off the coastal town of Sandakan early Wednesday, the report said.

"We still do not know the motive of their action," a security official was quoted as saying.

Only last week, Malaysian and Philippines security officials met in Kuala Lumpur and pledged to exchange intelligence in an attempt to crush cross-border crime.

But the porous nature of the border makes arms trafficking, piracy and the entry of illegal Filipinos into Malaysia problematic.

Sabah is located a short boat ride from the Philippine province of Mindanao where goverment forces are battling Muslim separatists.

The report said it could not be confirmed if the migrants were members of the Jemaah Islamiyah (JI), the regional terror network, or part of the Philippines Muslim separatist rebels, the Moro Islamic Liberation Frontwho are active in southern Philippines.

JI, which has been linked to Osama bin Laden's terror network al-Qaeda, aims to destabilise the region through terror attacks and bring Indonesia, Brunei, Malaysia, Singapore and the southern Philippines under a fundamentalist umbrella.

It has also reached out to Muslim organisations in Thailand and Myanmar, the International Crisis Group said in a report last year.

Malaysia has arrested more than 80 JI members, including some in Sandakan and other parts of Sabah state.

The 12,500-strong MILF has been waging a 25-year insurgency to establish an independent Islamic state in the southern Philippines.

The MILF signed a ceasefire agreement with the government here in 2001, but the pact was shattered in February when the Philippine military attacked a key MILF enclave to flush out alleged kidnapers, terrorists and other suspected criminals sheltered by the rebel group.

SPACE.WIRE