JAKARTA, Indonesia -- The al-Qaida network that carried out the terrorist attack in Bali is responsible for past plots against the United States in Southeast Asia, and is now planning to strike at Western students at international schools in Jakarta, Western and Indonesian officials said yesterday.

The plan to attack the schools was uncovered in the past few days, and officials said yesterday that the schools would remain closed until at least Wednesday.

Officials declined to say precisely how they had learned of the plot, but the United States and Australia have stepped up their electronic surveillance and intelligence-gathering here since the Bali attack, which killed nearly 200, most of them Australians.

Similar threat

The intelligence about the plot against the schools was as "specific in detail and of similar seriousness" to that which caused the Bush administration to order the closing of the U.S. Embassy here in September, the diplomat said.

That threat caused the United States to go on a heightened alert.

Based on the latest information gathered by Western intelligence agencies, diplomats said the planned attack was directed primarily at the Jakarta International School, an official said.

The school has 2,500 students, about a third of whom are Americans, on three campuses across this teeming city. It has classes from kindergarten through high school.

The Australian and British schools also planned to close, diplomats said last night.

Protecting the students is difficult not only at the school, officials said, but also on their way, because they typically travel on buses that take designated routes, or are driven by their parents in cars that bunch up outside the school before the class day.

The plotters are a cell within a larger al-Qaida network that has carried out several terrorist actions in Indonesia, and nearly succeeded in blowing up the American, Australian, British and Israeli embassies in Singapore in December, officials said yesterday.

That plot was thwarted by the Singaporean authorities. Investigators have concluded that the planners of the failed Singapore plot had moved their resources and efforts to Bali.

"It has all the similarities, the same modus operandi," said a Western intelligence official in the region.

A local cell bought the explosives and carried out surveillance, foreigners came in to provide expertise, and a high degree of secrecy or compartmentalization kept the locals from knowing who the foreigners were, intelligence officials say.

Six new suspects

In the investigation of the Bali bombing Oct. 12, Indonesian police announced six new suspects yesterday, who are at large.

The police said a 35-year-old computer expert, Imam Samudra, was the "field commander, planner and executor" of the attack. They also said he learned about explosives in Afghanistan in the mid-1990s and speaks English and Arabic.