Elusive Malaysian terror suspect Noordin Mohammad Top was behind a fatal jewellery store heist in Indonesia's Central Java province earlier this month.

The armed gang which raided the shop in the tourist town, killing the storeowner and his assistant before fleeing with nearly five kilograms of jewellery, was recruited by Noordin, a senior officer said.

"Based on police investigations, there are indications that the gold store robbery in Yogyakarta was carried out by Noordin M Top's group," said Indonesia's top detective, commissioner general Makbul Padmanegara.

Padmanegara said bullet casings found at the robbery matched those found after a shootout between police and Noordin's top accomplice, Azahari Husin, in his East Java hideaway last month.

But he refused to say whether the robbery was motivated by the militants' attempt to fund themselves for future attacks in Indonesia.

Azahari died in the shootout but Noordin remains at large after he managed to escape during a separate raid in Central Java last month.

Indonesia's intelligence chief Syamsir Siregar on Wednesday warned that Azahari's death could trigger revenge attacks and kidnappings for ransom.

Before his death, Azahari and Noordin had recruited an unspecified number of trained militants who were "capable of carrying out their jobs without being ordered by the two"' Siregar said.

He also warned the extremists could turn to kidnapping for ransom to fund their activities.

On high alert

Police and troops in the world's most populous Muslim nation have already been on high alert over the Christmas-New Year period amid fears of reprisal attacks following Azahari's death.

Azahari and Noordin were key members of the al-Qaeda-linked Jemaah Islamiah (JI) Islamic extremist network, blamed for the 2002 Bali bombings which killed 202 people as well as a string of other attacks in Indonesia.

Both are believed to have formed their own force after splitting from JI's mainstream command structure, which is concerned about heavy Muslim casualties in deadly JI blasts in recent years.

Documents found in Azahari's East Java hideaway also indicated that extremists were planning attacks over the holiday period.