That is Prime Minister Lee Hsien Loong's assessment.

It is not yet clear how Mas Selamat escaped, he added, but assured Singaporeans the Government would find out what went wrong and put things right.

'The escape is undoubtedly a setback and it should never have happened. As Minister Mentor said, it's the danger of complacency, of thinking that everything is all right.

'How did it happen? We're not absolutely sure yet. We've set up a Committee of Inquiry and it will find out what went wrong, and when we find out, we will put things right,' Mr Lee said yesterday.

These were his first comments on the matter since the escape of the former chief of the Singapore JI cell from Whitley Road Detention Centre on Feb 27.

Last Friday, Minister Mentor Lee Kuan Yew called the escape 'a very severe lesson in complacency'.

Yesterday, PM Lee also said that 'we're not infallible, if we are not careful we make mistakes'.

But with the various security agencies cooperating closely to apprehend Mas Selamat, he said: 'I think we have a good chance of catching him provided he's still in Singapore. We have no reason to think that he has left.'

Mr Lee did not believe the incident will cause people to think Singapore has gone soft on security.

'It's not done our reputation good but I don't think people believe we are just like any other place where you can have television sets and handphones and other things in jail. We're different. This was a lapse,' he said.

He stressed that the security forces must learn from the mistake and make sure not to repeat it as terrorism is a 'continuing problem' which Singapore is dealing with.

PM Lee also called on Singaporeans to close ranks to help the country recover from the setback.

'It is good to see the way that Singaporeans of all races have come together, come forward to help distribute posters, alert residents and maintain watch.

'So let us close ranks to deal with this, and bounce back to move forward - stronger, chastened, more on our guard, more alert than before.

'This strong spirit of solidarity is crucial in nation-building,' he said.

ZAKIR HUSSAIN