The police hope to track down six top leaders of militant group Jemaah Islamiah after the recent arrest of a suspected terrorist and the discovery of bomb-making chemicals, an intelligence official said today.

The suspect, Alias Osman, 36, was arrested in Kuala Lumpur on June 9 and led police to a cache of chemicals similar to the ones used in the Bali bombings in Indonesia last year which killed more than 200 people, mainly Western tourists.

He is being held as a suspected member of the al Qaeda-linked Jemaah Islamiah (JI) terror network accused of carrying out the Bali attack, the official told AFP on condition of anonymity.

Bomb expert

The chemicals, buried in a dustbin on a palm oil plantation in Perak, were labelled as potassium chloride, calcium chloride and aluminium powder.

"We found some chemicals, including some acids, and we have sent the chemicals for analysis to ascertain the contents," the official said.

"Alias was told to bury them on the plantation, but he has not told us who obtained them for him. He says he does not know what the chemicals were for."

The Malay Mail newspaper reported that there was about one kilogram each of potassium chloride amd calcium chloride in the bin, along with 14 detonators in the bin.

The paper said Alias had been trained by bomb-expert Azahari Husin, a Malaysian wanted by Indonesian police for his role in the Bali attacks.

Azahari is top of the list of six Malaysian militants being hunted throughout Southeast Asia.

Bounty on offer

"We believe they are currently under immense pressure wherever they are," the intelligence official said. "The regional situation in Indonesia and Thailand should help us in arresting the six."

Recent arrests in Thailand and beefed-up security laws in Indonesia showed the two countries were serious in the fight against terrorism, he said.

Malaysian police have offered a bounty of RM50,000 for the arrest of Azahari and the five other suspects -- Noor Din Mohamad Top, Shamsul Bahri Hussein, Amran Mansor, Zulkifli Hir and Zulkepli Marzuki.

Apart from the six "there are still a few hundred members of the Jemaah Islamiah who have gone underground here," the official said. "We are working hard to identify them and pick them up as soon as they resurface."

JI, which seeks to create a pan-Islamic state across Southeast Asia, is accused of aiming to destabilise the region through terror attacks.

Malaysia is already holding a total of 90 suspected Islamic militants, many of them alleged JI members, under the Internal Security Act which allows for detention without trial. - AFP