The Philippine military says it has not recovered the bodies of three senior Islamist militants killed Thursday in a U.S.-backed air raid on the remote southern island of Jolo.

A military spokesman says troops were still searching the jungle camp near Parang town for the remains of Umbra Jumdail, a leader in the Philippine-based Abu Sayyaf group, and Jemaah Islamiyah leaders Zulkifli bin Hir and Abdullah Ali. The three men were said to have been killed along with 12 other militants in Thursday's strike.

The spokesman says the troops have been hampered by gunfire from the surviving extremists.

Zulkifli bin Hir, a Malaysian national also known as Marwan, carried a $5 million reward for his capture offered by the United States.

Ali was a Singaporean national who went by the alias Muawiyah.

About 600 U.S. special forces have been deployed in the southern Philippines since 2002, providing support for the country's counterterrorism efforts.

Abu Sayyaf is responsible for a series of recent abductions in the southern Philippines, where Muslim rebels have been fighting government forces for self-rule since the 1970s.

The Jemaah Islamiyah network has been blamed for a series of terrorist attacks across Asia, including the 2002 Bali bombings that killed 202 people.