Jakarta, Indonesia ? The Muslim extremist network topping the list of suspects behind the Bali bombings is thought to be one of al-Qaida’s deadliest and closest allies, plotting violence in an effort to turn much of southeast Asia into an Islamic superstate.

In the past year, members of Jemaah Islamiyah which means Islamic Group have been tied to Sept. 11 hijackers, plots to destroy U.S. and other Western targets, and bombings at churches, shopping areas and nightclubs.

With increasing intelligence pointing to the group’s strong links to Osama bin Laden’s al-Qaida network, the United States on Wednesday branded the group a terrorist organization and asked the international community to dry up its assets.

Australia, which lost dozens of citizens in the attacks on the Indonesian resort of Bali two weeks ago, plans to make the same case to the United Nations in an effort to get the group outlawed internationally.

In a joint report prepared for the United Nations and obtained by The Associated Press, Australia and the United States wrote that the organization “has cells operating throughout Southeast Asia,” and two of its most senior leaders are Indonesian.

After months of denying there was any terror activity here, officials in Jakarta are now saying they believe al-Qaida and Jemaah Islamiyah may be operating in Indonesia.

Still, Indonesian Foreign Ministry spokesman Marty Natalegawa challenged “the perception that this is an Indonesia-based organization.

“Nobody knows where its real base is. A terrorist network is invisible and flexible in character. It can appear anywhere,” he said.

Jemaah Islamiyah’s goal is to build an Islamic state in Muslim areas of Southeast Asia, where some 250 million people are spread over southern Thailand, Malaysia, the southern Philippines and Indonesia.

Though the organization has been around for decades, it was linked to high-profile violence only in the past few years as Indonesia fell into turmoil and the group’s leaders were allegedly strengthening ties with al-Qaida.

According to the two-page U.S.-Australian report, classified as “confidential,” the organization has “established links to al-Qaida based on a shared ideology and cooperation in relation to terrorist activities.”

So far the group has been tied to:

A 2001 foiled plot to bomb the United States, British, Australian and Israeli embassies in Singapore. According to the U.S.-Australian report, Singaporean authorities believe the group was going to retaliate for the arrests by crashing a plane into Singapore’s international airport.

A grenade attack Sept. 23 at a house owned by the U.S. Embassy in Jakarta.

Threats that forced closure of U.S. embassies in Indonesia and other Southeast Asian countries around the anniversary of the Sept. 11 attacks.

Bombings outside a shopping mall April 21 that killed 15 people in the southern Philippines.

Bombings in December 2000 in Manila that killed 22 people.

Church bombings in Jakarta in December 2000 that killed 19 people.

Intelligence agencies have linked the attacks and plots to an Indonesian cleric named Riduan Isamuddin, also known as Hambali, who has reportedly built the organization in al-Qaida’s image. The U.S.-Australian report names him as the current leader of JI and as a “key figure,” linking the two groups.