MANILA, Philippines (AP) -- The Philippine military said it killed three of Southeast Asia's most-wanted terrorist leaders in a U.S.-backed airstrike that significantly weakens an al-Qaida-linked network that had used islands in the southern Philippines as a hideout and training base.
The dawn strike targeting a militant camp on a remote island killed at least 15 people, including Malaysian Zulkifli bin Hir, also known as Marwan, a top leader of the regional Jemaah Islamiyah terror network, said military spokesman Col. Marcelo Burgos.
The U.S. had offered a $5 million reward for the capture of Marwan, a U.S.-trained engineer accused of involvement in deadly bombings in the Philippines and in training militants.
Also killed Thursday were the leader of the Philippine-based Abu Sayyaf militants, Umbra Jumdail, and a Singaporean leader in Jemaah Islamiyah, Abdullah Ali, who used the guerrilla name Muawiyah, Burgos said. Police recovered the bodies, which were "positively identified by police and our intelligence informants at the site," Burgos said.
A U.S. official in Washington confirmed the strike on Jolo Island, an impoverished region 600 miles (950 kilometers) south of Manila, and said the Pentagon provided assistance in one of the region's most successful anti-terror operations in years. The strike debilitated a regional militant network that has relied on the restive southern Philippines -- sometimes called Southeast Asia's Afghanistan -- as a headquarters for planning bombings and a base for training and recruitment.
About 30 militants were at the camp near Parang town on Jolo, the stronghold of the Abu Sayyaf and their allies from the mostly Indonesian-based Jemaah Islamiyah, when it was bombarded by two OV10 aircraft dropping 500-pound (227 kilograms) bombs at 3 a.m., regional military commander Maj. Gen. Noel Coballes said.
"Our report is there were at least 15 killed, including their three leadership," he said. "This is a deliberate, fully planned attack coming from our forces."
The rest of the militants escaped and no one was captured, Coballes said.
However, two Philippine security officials with knowledge of the airstrike told The Associated Press that Marwan's body was not found, contradicting Burgos. The house where Marwar was believed to have been was shattered by bombs, the officials said.
They said the body of Jumdail, also known as Dr. Abu Pula, was buried Thursday. One of the officials said the dead included Jumdail's son, also an Abu Sayyaf fighter.
Both officials spoke on condition of anonymity because they were not authorized to talk to reporters.
American counterterrorism troops have helped ill-equipped Filipino troops track Marwan for years using satellite and drone surveillance. About 600 U.S. special forces troops have been deployed in the southern Philippines since 2002, providing crucial support for the Philippines' counterterrorism operations. U.S.-backed Philippine offensives have been credited for the capture and killing of hundreds of Abu Sayyaf fighters and most top leaders since the 1990s.
In Washington, a U.S. official, speaking to the AP on condition of anonymity because he was not authorized to speak on the record about the operation, confirmed the Pentagon had aided the strike. He was not specific about the contribution and did not know how many people had been killed in the operation.
Marwan's death would represent the most important success against Jemaah Islamiyah since the January 2011 arrest of Indonesian suspect Umar Patek in Pakistan's garrison town of Abbottabad, where Osama bin Laden was killed in a U.S. commando attack four months later.
Patek and Marwan allegedly collaborated with the Abu Sayyaf in training militants in bomb-making skills, seeking funding locally and abroad and plotting attacks, including against American troops in the southern Philippines.
Patek is believed to have returned to Indonesia then gone to Pakistan, leaving Marwan to take charge in the southern Philippines, military officials say.
The attack in Jolo also represents a huge blow to the Abu Sayyaf's ability to recover from years of setbacks through fund raising and training of militants.
The Philippine air force dropped four bombs from two planes, said Maj. Gen. Jose Villarete, head of the 3rd Air Division based at an air force base in Zamboanga city.
Abu Sayyaf is behind numerous ransom kidnappings, bomb attacks and beheadings that have terrorized the Philippines for more than two decades.
Jumdail had eluded troops in numerous offensives and emerged as a key figure in the radical movement.
Most recently, all three of the militant leaders were among the prime suspects in the kidnappings of three Red Cross workers from Switzerland, Italy and the Philippines in 2009. The hostages regained their freedom months later.
Abu Sayyaf militants, numbering about 400 by military estimates, are still considered a key threat to regional security and are suspected in the kidnapping of a former Australian soldier, as well as a Malaysian, a Japanese and an Indian.
On Wednesday, gunmen in nearby Tawi-Tawi island province seized Dutch and Swiss tourists. Officials said they were trying to move the hostages to Jolo.
Gomez contributed from Bangkok. Associated Press writers Oliver Teves in Manila, Philippines, and Pauline Jelinek in Washington contributed to this report.