The Philippine military said Friday Malaysia would send forensics experts in an effort to obtain proof that Filipino forces had killed three of Southeast Asia's most-wanted terror suspects.

The military said its US-backed airstrikes last week on a remote southern island killed three senior leaders from the Al Qaeda-linked Jemaah Islamiyah (JI) and Abu Sayyaf networks, as well as 12 junior figures.

But it was not able to immediately provide proof, with authorities saying bodies had been taken away by fellow militants and quickly buried in line with Muslim custom.

Philippine military spokesman Colonel Arnulfo Burgos said Friday police had gathered pieces of human tissue and blood after the strike on the southern island of Jolo.

Philippine police will now liaise with the Malaysian team over the forensic evidence, Burgos said.

"This would help the Armed Forces of the Philippines provide proof that the terrorists Mauwiyah and Marwan are already dead," Burgos told reporters, without saying when the Malaysian team would arrive.

The highest-profile militant reported slain was Malaysian Zulkifli bin Abdul Hir, alias Marwan, one of the United States' most-wanted terror suspects with a $5 million bounty on his head from the US government.

Zulkifli was one of JI's top leaders and a bomb-making expert who had been hiding out in the southern Philippines since 2003, according to the US State Department.

The Malaysian forensics experts are expected to obtain DNA samples from Zulkifli's relatives before they fly to the southern Philippines to compare samples, Burgos said.

Also reported killed was Singaporean Mohammad Ali, alias Muawiyah, another JI leader who had been hiding in the Philippines since the group killed 202 people in a series of bomb attacks on the Indonesian island of Bali in 2002.

The third senior militant reported killed was Filipino Abu Pula, also known as Doctor Abu or Umbra Jumdail, one of the core leaders of the Abu Sayyaf that is blamed for the worst terrorist attacks in the Philippines.

The US military, which has a small team of US Special Forces providing counter-terrorism training in the southern Philippines, helped in the attack by providing intelligence support, Filipino military officials said.

However the US government has declined to comment on whether the three senior terrorists suspects were definitely killed.

US Secretary of State Hillary Clinton's senior advisor on political-military affairs, Andrew Shapiro, declined to discuss details of the incident when talking to reporters in Manila, deferring questions to the Philippine military.