THE hunt for Mas Selamat Kastari has flushed out 66 illegal immigrants.

Some were caught by the network of 'trip wires' set up by the authorities to snag the fugitive terrorist in case he takes cover in places like forests where the search forces have already combed.

Giving the media an update on the manhunt for the Singapore Jemaah Islamiah leader, who fled from the Whitley Road Detention Centre on Feb 27, police operations director Wong Hong Kuan said the 'trip wires' included surveillance equipment and 'human eyes and ears' to ferret out the 47-year-old fugitive.

These are part of a three-prong strategy to recapture Singapore's most wanted man, whose face is plastered on 210,000 posters, fliers and 10,000 postcards.

Assistant Commissioner Wong said the other two strategies to tighten the dragnet are to deny Mas Selamat space here and ensuring that he remains on the island.

Nearly four million MMSes and emails have been sent out to mobile phone users seeking their help to track down the runaway. Police have so far received more than 1,400 calls and emails giving various leads and tip-offs.

'We will press on to deny him the space and opportunity to plot his escape,' AC Wong said.

Even the arrested illegal immigrants said they have seen posters of Mas Selamat, he added. Security watchgroups, private security officers and coastal communities have also been briefed to look out for him, while the borders remain locked down.

The authorities believe that Mas Selamat is still somewhere on the island. AC Wong gave two reasons for this deduction.

As soon as the escape was discovered, the checkpoints were 'secured' within 30 minutes, with immigration officers carrying out 100 per cent departure checks.

Added to the belief that Mas Selamat escaped with no help, the authorities think he is unlikely to have fled Singapore. Malaysia and Indonesia shared similar assessments, AC Wong said.

'It'll be his instinct to try to find a safe place to hide and wait for the initial search effort to die down before he moves to escape,' he said. 'He's a very cautious person by nature.'

There has been no let up in the search operations, which could involve up to 3,000 officers, depending on the scale. On Sunday, security forces combed the MacRitchie Reservoir.

AC Wong said the search forces are given 'proper rest and relief' as the authorities are determined to pursue the fugitive to the end.

'We just need to continue with our efforts to make sure we sustain it, and not have this doubt in our mind that he's not in the country and therefore we should just call it off,' he said.

'For that's precisely what he wants. For us to have a doubt, for us to relax our guard, so he has the opportunity to escape.'

Police on Sunday also gave an additional description of Mas Selamat, who walks with a limp. AC Wong said he also has a mole just below his right eye, and small, pursed lips.