SINGAPORE - Singapore boasts one of the world's most efficient intelligence gathering networks. So when suspected al-Qaida terrorists were arrested here on suspicion of plotting to blow up the U.S. Embassy, it sent an alarming message: If terrorists can hide in Singapore, they can hide anywhere.
The discovery of a suspected homegrown cell connected with al-Qaida shocked the Southeast Asian city-state of 4 million people. While Islamic militants have been active in neighboring Indonesia, Singapore has been an oasis of stability in the turbulent region.
Malaysia and some trained at al-Qaida camps in Afghanistan.
The 15 were arrested after authorities found bomb-making information and photographs and video footage of the U.S. Embassy and other buildings in the suspects' homes.
The government said the suspects also had al-Qaida-linked materials, fake passports and forged immigration stamps.
The detentions coincided with arrests of suspected militants in Malaysia and Indonesia, raising fears of a wide terrorist network in Southeast Asia linked to Osama bin Laden, chief suspect in the Sept. 11 attacks on New York and Washington.
Defense analyst Andrew Tan called the discovery "shocking."
"But it's inevitable that there is a small fringe attracted to Osama bin Laden and the extremist brand of militancy which Osama preaches," said Tan, who is with Singapore's Institute of Defense and Strategic Studies.
About 15 percent of Singaporeans are Malay Muslims. Most Singaporeans are Chinese. Most public protest is banned, so there have been no demonstrations against the war in Afghanistan.
Muslim government ministers and some religious leaders have praised Singapore's crackdown.
But Zulfikar Mohamad Sharif, director of the Singaporean Muslim rights group Fateha, has questioned the government's evidence against the 15 detainees and has called for a trial.
The suspects were arrested under the Internal Security Act, which allows for indefinite detention without trial.
The U.S. State Department applauded Singapore for thwarting the alleged plot to blow up the embassy and American economic interests on the island. Some, including Defense Minister Tony Tan, have said Singapore's close links to Washington could make it a target for terrorism.
Singapore is a "perfect target" for attacks on U.S. assets outside the United States, says Paul Evans, an Asian security expert from the University of British Columbia in Canada.
About 17,000 Americans live in Singapore. Almost 6,000 multinational companies - many of them American - have regional offices in the affluent city-state and American companies are among the biggest employers in Singapore.
The U.S. Navy has a logistics unit in Singapore and warships going to and from Afghanistan have been resupplied in the city-state. Last year, Singapore opened a deep water port to accommodate U.S. aircraft carriers.
But terrorists planning attacks in Singapore face a tough adversary. "It's so heavily policed," Evans said. "You've got a tightly regulated society and an effective intelligence agency here."
The intelligence agencies in Southeast Asia say they are sharing information to foil terrorist plots. Susilo Bambang Yudhoyono, Indonesia's top security minister, said the countries were "looking together to solve problems" related to terrorism.
Hadi Soesastro, director of the Center for Strategic and International Studies in Indonesia, said the Indonesian government has become more determined in dealing with radical Muslim groups recently. Regional intelligence sharing has improved since the 10-member Association of Southeast Asian Nations adopted a plan in November to fight transnational crime, he said.