A key Bali (search) bombing suspect admitted in court Wednesday that he was the operational chief of the Southeast Asian terror group Jemaah Islamiyah (search), and said he knows Usama bin Laden (search) "very well."

Ali Ghufron, alias Mukhlas, testified at the treason trial of Abu Bakar Bashir (search), a Muslim cleric and the alleged spiritual head of Jemaah Islamiyah.

Mukhlas told a packed courtroom he took over as the operations chief after his predecessor, Riduan Isamuddin, alias Hambali, went into hiding.

"My followers chose me to replace Hambali after he left," he said.

Mukhlas was arrested last year for allegedly masterminding the Oct. 12 Bali bombings, which killed 202 people. He is facing trial on terror charges for the attack, the deadliest since Sept. 11, 2001.

During Mukhlas' testimony, a judge asked him if he knows bin Laden, who allegedly orchestrated the Sept. 11 attacks.

"I know him very well," Mukhlas said, adding that bin Laden was not financially involved in the Bali bombing.

Officials say Jemaah Islamiyah is allied to bin Laden's Al Qaeda network and that its aim is to declare a pan-Islamic state across Southeast Asia.

Mukhlas was one of four key suspects in last year's Bali bombings to testify Wednesday at Bashir's trial.

Bashir, 64, is not accused of the Bali bombings. He is on trial for allegedly plotting to overthrow Indonesia's government and is accused of ordering a series of church bombings in 2000 that killed 19 people.

If convicted, he could face the death penalty.

Bashir flatly denied involvement with Jemaah Islamiyah while his supporters in the packed courtroom repeatedly interrupted proceedings with cries of "Allah is great!"

Prosecutors had hoped the four witnesses would reveal their links to Bashir and possibly provide evidence of his terror role -- not just in the 2000 church blasts, but also the Bali attacks.

They got a mixed result.

Some joked during their testimony or gave muddled answers. Others waved at photographers and news crews.

One witness, Imam Samudra, testified that Bashir played no part in that attack or any other bombings.

The two other Bali suspects, Ali Imron and Hutomo Pamungkas, alias Mubarok, suggested that Bashir might be the spiritual head of Jemaah Islamiyah.

Mubarok agreed that Bashir headed Jemaah Islamiyah. A judge pointed to Bashir and said: "Do you mean this man?" Mubarok responded: "Yes."

Imron said he had heard only from others that Bashir took over as the group's leader in 2000 after the death of its founder, Abdullah Sunkar.

"As far as I know, his (Sunkar's) replacement was Abu Bakar Bashir," Imron said.

At another point, Imron said he was unsure who led the group.

Asked by a judge to respond to Imron's testimony, Bashir said: "I have met him two or three times. ... But his 'feeling' that I am the head of Jemaah (Islamiyah) is not true."

In a related development, three Muslim men -- two Thais and an Egyptian -- were charged in Cambodia with international terrorism and links with Jemaah Islamiyah, officials said.

The three, who were arrested Sunday, were identified as Abdul Azi Haji Thiming and Muhammad Jalaludin Mading of Thailand, and Esam Mohammed Khidr Ali of Egypt.

If convicted, they face 20 years in prison.