Kuala Lumpur, Malaysia ? When Yazid Sufaat arrived home to Malaysia after months in southern Afghanistan, police were waiting.

Authorities say his arrest has helped expose a Southeast Asian terror network that has surprised governments and security experts. They say its structure and capacities are frighteningly similar to Osama bin Laden’s al-Qaida organization.

Since December, Singapore, Malaysia and the Philippines have all announced arrests of purported cell members suspected of involvement in a plot to blow up the U.S. Embassy in Singapore, Navy ships and other pro-Western targets in the wealthy city-state.

Philippine National Security Adviser Roilo Golez said there are indications that the militant group, which uses the name Jemaah Islamiyah, has become “very active.”

Investigators say its aim is to spread radical Islam across the region  a concept with scant support among a majority of the region’s Muslim residents. Indonesia and Malaysia are both Muslim-majority nations, but their governments are secular. The Philippines is mostly Roman Catholic, while Singapore is mostly Christian or Buddhist.

Malaysian authorities say in that country, as many as 200 people are members of Kampulan Militant Malaysia, a group with ties to Jemaah Islamiyah. They include Yazid, who is suspected of training in al-Qaida camps and playing host to two of the Sept. 11 hijackers two years ago at his weekend home. He was arrested Dec. 9 as he crossed from Thailand into Malaysia.

As authorities across the region piece together information gleaned from separate investigations, they say it has become increasingly clear that the group was linked to al-Qaida and possibly hoped to emulate it.

An Indonesian man in Philippines custody since Jan. 15 told authorities there that he financed bombings that killed 22 people in Manila in December 2000 with Jemaah Islamiyah money, according to affidavits given to prosecutors Friday.

In the sworn statements, Fathur Rohman Al-Ghozi, 31, said he joined the group while he was a student in Pakistan in 1990 to 1995. His arrest led authorities two days later to more than a ton of explosives and 17 M-16 rifles in southern General Santos city in the Philippines. In the affidavits, al-Ghozi said those explosives were intended for attacks in Singapore.

“All this definitely shows a terrorist organization that is working across the region, and not just in Singapore” said Dana Robert Dillon, a Southeast Asia specialist at the Heritage Foundation, a Washington-based think tank.

The structure of the network  individual cells operating independently but able to call on each other for help in specific tasks  was comparable to al-Qaida, Dillon said.

FBI Director Robert S. Mueller recently said for the first time that some of the planning for the Sept. 11 terror attacks on the United States took place in Malaysia.

U.S. authorities have praised cooperation from both Malaysia and Singapore, and the United States sent troops to help train the Philippine military in its fight against militant Islamic groups there.