MANILA, Philippines – Two of the most dangerous Al Qaeda-linked groups in Southeast Asia are working together to train insurgents in scuba diving for seaborne terror attacks, according to the interrogation of a recently captured guerrilla.

The ominous development is outlined in a Philippine military report obtained yesterday that also notes increasing collaboration among the Muslim rebels in other areas, including financing and explosives, as extremists plot new ways to strike.

In the past year, the Indonesia-based Jemaah Islamiyah has given Abu Sayyaf insurgents in the Philippines at least $18,500 for explosives training alone, the report said.

The report comes a month after the American Coast Guard announced it is seeking to better protect the nation’s ports from terrorist attacks by scuba divers by developing a sonar system that can distinguish human swimmers from dolphins.

Concerns about terrorist strikes by scuba divers were raised three years ago after the FBI announced it was investigating whether Al Qaeda operatives took scuba training to help blow up ships at anchor, power plants, bridges, depots, or other waterfront targets.

Authorities fear scuba divers could target ships with more accuracy than a small explosive-laden boat like the one used in the USS Cole blast that killed 17 sailors in 2000 in Yemen.

According to the Philippine report, an Abu Sayyaf suspect in a deadly bus bombing in Manila on February 14 – Gamal Baharan – described how he and other seasoned guerrillas took scuba diving lessons as part of a plot for an attack at sea.

Abu Sayyaf leaders Khaddafy Janjalani and Abu Sulaiman initiated the training, Mr. Baharan said, adding that Mr. Janjalani claimed to speak directly with Al Qaeda leader Osama bin Laden via satellite phone. Authorities couldn’t verify any such conversations and said Mr. Janjalani may have been boasting, according to Philippine military officials, speaking on condition of anonymity. Mr. Baharan, 35, said he was told in October to undergo the scuba training in southwestern Palawan province, where he periodically received cell-phone messages from Mr. Janjalani and Mr. Sulaiman “asking him how many fathoms he would be able to dive,” the report said.

The training was in preparation for a Jemaah Islamiyah bombing plot on unspecified targets outside the Philippines that require “underwater operation,” Mr. Beharan is quoted as saying.

Jemaah Islamiyah has been blamed for a string of attacks in Southeast Asia starting in 1999. Major strikes include the August 5, 2003, bombing of the J.W. Marriott hotel in the Indonesian capital, Jakarta, which killed 12 people, and the October 12, 2002, bombings on Bali Island that killed 202, mostly foreign tourists. Three dozen alleged members were convicted in the Bali bombings and more than a dozen in the Marriott bombing.

Abu Sayyaf is known more for its kidnap-for-ransom schemes – including many involving Americans and Western tourists – and conducting deadly raids against Christian towns.

More recently, Abu Sayyaf has been accused of more spectacular explosive attacks, including the almost simultaneous bombings in Manila and two southern cities February 14 that killed eight people and wounded more than 100. Those attacks came a year after a bomb blew up on a ferry in Manila Bay, killing 116 people in the Philippine’s worst terrorist strike.

Although Abu Sayyaf’s ranks have been largely depleted by American backed military assaults, the government still considers the group a major threat. Such concerns were highlighted by a botched jailbreak Monday in which Abu Sayyaf suspects seized guards’ weapons in a melee that left five people dead. A 29-hour standoff ended when police stormed the prison in a hail of gunfire Tuesday and killed 22 inmates, including 19 Abu Sayyaf members – three of them prominent commanders – who faced charges for kidnappings and bombings.

The inmates were buried Wednesday in a mass grave in a large Muslim community in Manila’s Taguig suburb. Their bloody remains were not cleaned and were wrapped in white cloth – a local practice that indicated they were regarded as martyrs.

Many relatives of the dead have criticized the government, believing the inmates were killed in cold blood and falsely made to appear to have put up a fight with smuggled weapons.

Abu Sayyaf leader Mr. Sulaiman has warned of revenge, leading police to tighten security.

Mr. Baharan claimed Mr. Janjalani is alive – contrary to speculation that he was killed in a military air strike – and he said Mr. bin Laden would only speak to the Abu Sayyaf chieftain.