MANILA, Philippines (AP) — The Philippine military said it killed Southeast Asia’s most-wanted terrorist and two other senior militants Thursday in a U.S.-backed airstrike marking one of the region’s biggest anti-terrorism successes in recent years.

The dawn strike targeting a militant camp on a southern Philippine island killed Malaysian Zulkifli bin Hir, also known as Marwan, a top leader of the regional, al Qaida-linked Jemaah Islamiyah terror network, said military spokesman Col. Marcelo Burgos.

Also killed were the leader of the Philippines-based Abu Sayyaf militants, Umbra Jumdail, and a Singaporean leader in Jemaah Islamiyah, Abdullah Ali, who used the guerrilla name Muawiyah, Burgos said.

The strike significantly weakens a regional militant network that has relied on the restive southern Philippines — sometimes called Southeast Asia’s Afghanistan — as a hideout, a headquarters for planning bombings and a base for training and recruitment.

Police recovered the bodies of the three militant leaders, and they were “positively identified by police and our intelligence informants at the site,” Burgos told The Associated Press. “What I know is that they will be buried.”

About 30 militants were at the camp near Parang town on Jolo Island, the stronghold of the Abu Sayyaf and their allies from the mostly Indonesian-based Jemaah Islamiyah, when it was bombarded by two OV10 aircraft 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 after the attack, Coballes said.

The U.S. had offered a $5 million reward for the capture of Marwan, a U.S.-trained engineer accused of involvement in a number of deadly bombings in the Philippines and in the training of new militants.

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 a crucial support for the Philippines’ counterterrorism operations.