ONE question dominated local Internet forums, from HardwareZone to VR-zone, yesterday: How did the head of the Jemaah Islamiah (JI) terror network in Singapore, Mas Selamat Kastari, manage to escape?

Netizens wondered how such a security lapse at the Whitley detention centre could have happened. Singapore's most wanted man, who had plotted to crash a hijacked plane into Changi Airport, is still missing at press time. He escaped from the detention facility at about 4.05pm on Wednesday.

Netizens reacted largely with disbelief, with many hoping Mas Selamat would be captured soon. VR-zone's cyberdog said: "I hope they catch him soon, if not, we all better stay at home, don't go to work tomorrow. Not safe."

One contributor known as commentator_sc called the escape "incredible" on straitstimes. com and wondered about the delay in alerting the public.

He said: "It can't be to deny knowledge to the JI (members) since they would be among the first to know."

Mr Siow Jia Rui, 32, a my paper reader, also wanted to know more.

He said in an e-mail: "With a world-class security apparatus in place, I find it ridiculous that a middle-aged man who has difficulty walking can make it out of the detention centre with such ease."

A Singapore Chinese Girls' School student even posted on Straitstimes.com's forum that she is too distraught to go to school.

JuliaEileen said: "Social studies has made me scared stiff over such issues."

But experts on terrorism say that while the fugitive terror leader may try to get in touch with Indonesia's most wanted militant Noordin Mohd Top and other JI leaders if he escapes to the archipelago, it is unlikely that he will be able to launch a significant attack in the region.

The Straits Times quoted Ms Sidney Jones, the head of the Jakarta chapter of the International Crisis Group, which has regularly monitored the JI, as saying: "He certainly is a very dangerous individual, but I don't think his escape significantly enhances the risk of a terror attack in the region."

HardwareZone's panda-san felt that the lapse in security was "an honest mistake".

Many contributors also gave their thumbs up to the government for being able to keep the country safe thus far. jockstrap posted on Straitstimes. com: "Seriously though - SG (Singapore) has done a good job so far in monitoring and surveillance, so these kind of people can't wreak havoc. I have confidence that they will round this guy up fast."

Yesterday, more than 100 Singapore Armed Forces soldiers were mobilised to join the intensified, island-wide land, sea and air hunt for the fugitive.

Others stressed that finding the detainee was the priority now, while finding out what happened or even whose mistake it was, should come after. jchlee highlighted on Straitstimes. com that "even with the tightest of security measures, an inmate can and will escape if they spend enough time planning it, and have extremely good luck".

He added: "I would suggest that as Singaporeans, let's all keep a lookout for this damn fella. Before he really wreaks havoc in Singapore."

Meanwhile, in neighbouring Malaysia, the police have stepped up security on the border.

Musa Hassan, inspector general of police, said security forces have beefed up patrols and have distributed photos of Mas Selamat to various enforcement agencies, the AFP reported. Mohamad Mokhtar, police chief of Johor, was co-ordinating with Singapore police in the manhunt