Zarkasih, identified for the first time as JI's overall leader, was captured Saturday on Java island hours after Abu Dujana, said Brig. Gen. Suryadarma Salim. Six other senior militants were also arrested, he said.

Like other top Jemaah Islamiyah leaders, Zarkasih went by several aliases and underwent military training in Afghanistan in the late 80s.

"I became the emergency head ... in 2005," Zarkasih, 45, said in a videotape shown to reporters, adding that the selection followed a police crackdown that crippled the organization in recent years.

The capture of Dujana, who as head of Jemaah Islamiyah's military unit had been Indonesia's most wanted man, was announced Wednesday. Authorities had mostly referred to him as the group's top leader, but said Friday, after intensive interrogations, that Zarkasih held that post.

"From 2005 until now I was head of the military wing (of Jemaah Islamiyah)," said Dujana in another videotape Friday.

Officials say Jemaah Islamiyah wants to create an Islamic state - violently if necessary - in Muslim parts of Southeast Asia, but it has long been split on whether bombing civilian or "soft" targets assisted in this goal.

Its supporters have been blamed for the 2002 bombings on Indonesia's Bali resort island; the 2003 and 2004 attacks on the J.W. Marriott Hotel and the Australian Embassy in Jakarta; and the 2005 triple suicide bombings on restaurants in Bali.

The attacks - some of which police say were carried out with funds and direction from al-Qaida - together killed more than 240 people, mostly Western tourists.

Aided by U.S. and Australian funds and expertise, anti-terror police have arrested about 300 militants in recent years. Five have received death sentences and many others have received long sentences.

Among those previously arrested were Abu Rusdan and Abu Bakar Bashir, both of whom police and former militants have said led Jemaah Islamiyah in the early 2000s.

Bashir was found guilty of giving his blessing to the 2002 Bali attacks, but after more than three years in jail his conviction was overturned. Rusdan served 2 1/2 years for sheltering a known terrorist.

Both are now free men and returned to preaching an uncompromising brand of Islam.

Analysts and former Jemaah Islamiyah members say its leaders likely did not know about the bombing plots. Indonesia has not made membership of the group, which was formed in Malaysia in the late 90s, a criminal offense.