The alleged operations chief of Jemaah Islamiyah has confessed to belonging to the Al Qaeda-linked group and to taking part in the Bali bombings that left nearly 200 people dead, police said Thursday.

Police arrested Mukhlas, alias Ali Gufron, and eight others in a series of raids late Tuesday on the central Indonesian town of Solo.

"Mukhlas, alias Ali Gufron, has confessed to be a member of Jemaah Islamiyah," which is widely believed to be responsible for the Oct. 12 bombings in Bali, Maj. Gen. I Made Mangku Pastika Pastika told reporters.

Pastika said Mukhlas also admitted to participating in meetings July and August to plan the Bali blasts.

Meanwhile, a senior Malaysia official said Thursday the arrest of Mukhlas was a cooperative effort, with Australia providing the technical prowess and Malaysia and Singapore the intelligence of his whereabouts.

The official, speaking on condition of anonymity, also hailed the arrest of Mukhlas, saying he could provide authorities with crucial information on other top Jemaah Islamiyah leaders, including the whereabouts of Riduan Isamuddin, known as Hambali.

Intelligence officials have said Hambali handed over the day-to-day running of Jemaah Islamiyah to Mukhlas and is now on the run in Pakistan.

"This is a real chance to get Hambali wherever he may be — in Pakistan or Indonesia," the official said. "So far, his whereabouts has been mostly guesswork but now, with Mukhlas's capture, the leads can be further narrowed down."

But other diplomats played down the importance of the Mukhlas arrest. One Asian intelligence official said it remained unclear who Mukhlas is and what, if any role, he plays in Jemaah Islamiyah. And even he is a central figure, the official warned there are plenty of other Jemaah Islamiyah members out there ready to launch attacks.

Indonesian police have stopped short of implicating Jemaah Islamiyah in the blasts. However, regional and U.S. government officials have alleged the group was behind the attacks and several other foiled plots on Western interests in Singapore.

Wednesday's arrests brought the number of people arrested in the Indonesian investigation to 28. None have been charged.

Also under detention is the spiritual leader of Jemaah Islamiyah, Abu Bakar Bashir. He has not formally been named as a suspect in the Bali bombings, but he was arrested after the attack on separate charges of masterminding an earlier string of church bombings in 2000.

Bashir, 64, founded a hardline Islamic boarding school based in Solo and is an open admirer of Osama bin Laden.