K By Richard C. Paddock

UTA, Indonesia – Last month’s deadly bombing on the island of Bali was carried out by a computer-savvy group of Indonesian Muslims with links to previous anti-Christian terror attacks, police said Sunday.

Providing the most comprehensive picture to date of the group believed responsible for the attack Oct. 12 that killed 191 people, police said the operational leader was a university-trained engineer known as Imam Samudra who probably learned how to make bombs in Afghanistan.

Police Gen. I Made Mangku Pastika, who is heading the investigation, released sketches and photographs of six suspects including Samudra, whom he described as the “highly mobile field commander” of the attack.

Pastika said he believes all six are still in Indonesia and appealed to the public to report their whereabouts.

The general said Samudra was a “calm” and “intellectual” man who stayed in Bali for four days after the attack to see what police were learning. He has almost always been seen wearing a hat and carrying a laptop computer case, Pastika said.

Other alleged participants in the plot included a “genius” electronics expert and bomb maker, a teacher at an Islamic school who buried a stash of automatic weapons in the woods near his village and a graduate of an Islmaic school in Malaysia who rented a room in Bali for the group to assemble their bombs. Two of the six are Indonesians of Arab descent.

Samudra, who was born Abdul Azis, has used at least eight names, police say.

“They change their names every time,” Pastika said. “For one operation, one name.”

Samudra has been wanted by Indonesian authorities since early last year for his alleged role in the bombing of two dozen churches on Christmas Eve 2000. Nineteen people in 10 cities died in those attacks.

Indonesian police have arrested radical Islamic cleric Abu Bakar Bashir for his role in the same church bombings. Bashir denies any part in terrorism but is accused of heading Jemaah Islamiah, a regional terror network believed responsible for numerous attacks in at least three countries.

Police have yet to produce evidence that Bashir and Samudra know each other, but Samudra’s role in the Bali bombing could be pivotal. Pastika said police are searching for the “missing link” that could tie Bashir to the bombing participants.

Police said earlier this year that Samudra had conspired to carry out the church bombings with Riduan Isamuddin, a close associate of Bashir better known as Hambali. He is believed to be Jemaah Islamiah’s operations leader and a top al-Qaida operative who has masterminded terror attacks in Southeast Asia for nearly a decade.

In a February interview, police Gen. Saleh Saaf described Samudra and Hambali as “one team.”

Pastika said Samudra went to Afghanistan during the Soviet occupation and again during the mid-1990s. Samudra also reportedly visited Malaysia while Bashir and Hambali were living there in self-imposed exile and may have met them there.

Police suspect that Hambali initiated the Bali bombing. According to a recent report in the Asian Wall Street Journal, he convened a meeting of Jemaah Islamiah leaders in southern Thailand in January and ordered them to attack “soft” targets, such as nightclubs frequented by Westerners.

Police say they got their biggest break in the Bali investigation when they traced the chassis number of the minivan used in the attack and arrested the owner, Amrozi, a co-founder and part-time teacher at the Al-Islam boarding school in his East Java village of Tenggulun.

Amrozi confessed that he participated in the Bali bomb plot and told police that he began helping Samudra acquire materials to make bombs in 2000.

According to the police, Amrozi said the two first met to plan the Bali attack on Aug. 2 in the Central Java town of Solo . Amrozi reportedly said Samudra instructed him to buy the minivan and chemicals for the attack and deliver them to Bali.

The money to pay for the materials was delivered by a suspect named Idris, also known as Jhoni Endrawan, who was the deputy leader of the group and took charge of logistical arrangements and disbursing cash, police say.

Earlier this month, police focused their investigation on the Al-Islam school in Tenggulun, which they said was the headquarters of the Bali plot.

But police now say the main suspects are seven militants from different parts of Indonesia, including two affiliated with the school – Amrozi and his brother, Ali Imron, an Al-Islam teacher who allegedly buried automatic weapons and ammunition in PVC pipes nearby.

Police are looking for at least two more of Amrozi’s brothers connected with the school, including Gufron, a radical Islamic teacher who allegedly helped inspire Amrozi to embrace extremist views. By some accounts, Gufron, also known as Mukhlas, is a top Jemaah Islamiah leader.

Pastika said police reconstructed the Bali attack and concluded that three bombs went off within 11 seconds of one another, two in the beach town of Kuta and one in the capital city, Denpasar.

Investigators have said that Ali Imron was the one who detonated the bombs, but police now believe it was a member of the group known as Dulmatin, an electronics expert considered by his junior high school teachers to be a genius.

Pastika said the first bomb was delivered to Paddy’s Irish Club by Umar, a Muslim from the island of Flores. He allegedly walked into the bar with the bomb and left it there minutes before the attack. It killed eight people when it exploded at 11:08 p.m.

Six seconds later, a huge bomb in Amrozi’s minivan exploded across the street outside the Sari Club, destroying both nightclubs and two dozen nearby buildings.

Five seconds later, a bomb exploded in Denpasar outside the honorary U.S. Consulate there. Pastika said that the bomb might have caused serious damage but that the bombers could not get close to the consulate that evening because of a motorcycle race that blocked traffic. The bomb exploded outside the consulate wall, and no one was injured.