SINGAPORE -- Suspected al-Qaida members armed with bombmaking instructions were planning to attack the U.S. embassy and American businesses in Singapore, the island's government said Monday.
The 15 suspects -- some of them members of Singapore's military -- were detained last month after authorities found bomb information along with photographs and video footage of targeted buildings in their homes and offices.
"The U.S. Embassy and U.S. commercial entities were the principal targets," said Ong-Chew Peck Wan, a spokeswoman for the Home Affairs Ministry.
The arrests of the suspects, 14 Singaporeans and one Malaysian, were announced Saturday.
Investigators also found materials linked to Osama bin Laden's al-Qaida network, along with falsified passports and forged immigration stamps, according to the Home Affairs Ministry, which oversees police and internal security. Some of the suspects may have trained at al-Qaida camps in Afghanistan, the government said.
The suspects also have ties to militant groups in Malaysia and Indonesia, the ministry said in a statement. Malaysian police have arrested 13 people since Dec. 9 on suspicion of being members of an extremist group with possible links to three men accused of involvement in the Sept. 11 attacks in the United States.
The 15 arrested in Singapore were detained under a law that allows certain suspects to be held indefinitely without trial. Two Singaporean civil rights groups -- the Think Center and Fateha.com -- urged prompt trials for the suspects.
Defense Minister Tony Tan told Singapore's NewsRadio that the country was vulnerable to terrorism because of its close links with the United States.
An estimated 17,000 Americans live in Singapore. About 6,000 multinational companies -- many of them American -- have regional offices in the wealthy, highly modernized Southeast Asian country of 4 million people.
Nicholas de Boursac, head of the Singapore American Chamber of Commerce, said the arrests were "very positive news for the business community ... being further evidence of Singapore's and Malaysia's vigilance on this issue."
Singapore and the United States also have close military relations. Singapore recently opened a new naval facility built specifically to accommodate U.S. aircraft carriers. The island also is home to a U.S. Navy logistics unit.
Security around embassies and other sensitive areas in Singapore has been beefed up. Police on Monday set up a roadblock outside the Israeli Embassy, and armed Gurkhas -- elite Nepalese fighters sometimes hired to protect sensitive areas in Singapore and other countries -- were guarding Singapore's American Club.
Gurkhas have been guarding the U.S. Embassy since Sept. 11.
A U.S. Embassy official said on condition of anonymity that Singapore and the United States were "cooperating closely" and that the United States was confident Singapore could secure U.S. interests on the island.