Jemaah Islamiyah, which officials say wants to create an Islamic state across much of Southeast Asia, has been blamed for the 2002 bombings on the resort island of Bali, the 2003 and 2004 attacks on the J.W. Marriott Hotel and the Australian Embassy, and the 2005 triple suicide bombings on restaurants in Bali.
Together, the attacks killed more than 240 people, many of them Western tourists.
Jemaah Islamiyah, which police say received funds and direction from Al Qaeda in the early 2000s, has also been blamed for attacks in the Philippines, and Malaysia and Singapore have arrested several dozen alleged operatives.
Adiwinoto said Dujana played a major role in "almost all" of the bombings in Indonesia, but he gave no more details.
He said Dujana's Arabic language skills meant he forged close ties with Al Qaeda commanders in Afghanistan in the late 1980s and 1990s and -- like scores of other militants -- met bin Laden.
"He can assemble bombs and he can recruit members, so he is more important" than other key terror suspects Noordin Top, a Malaysian who remains at large, and explosive's expert Azahari bin Husin, who was shot and killed in a raid in 2005, he said.
Abu Rusdan, the man police say Dujana replaced as head of the group in 2003, said his former comrade was the last of the old generation of Jemaah Islamiyah still on the run, referring to Afghan veterans who studied under the movement's founder, Abdullah Sangkar, in Malaysia in the 1990s.
"The JI mainstream has now finished," he told the Associated Press, cautioning that splinter groups could still launch attacks. "He was the last of the line."
Security specialists called Dujana's capture a major breakthrough, saying he could provide crucial information. But they played down police claims of his direct involvement in the bombings.
"On a symbolic level, it's great," Ken Conboy, a Jakarta-based analyst on Southeast Asian terror groups, said of the arrest. "With his seniority, he played a significant role in recruiting."
Dujana was not on any known US list of terror suspects. Most analysts say Top is a more dangerous terrorist.
