Southeast Asia's most-wanted terrorist is dead after a U.S.-backed airstrike in the Philippines, the country's military officials announced Thursday.
   
Malaysian Zulkifli bin Hir, also known as Marwan, was a top leader of the regional al Qaeda-linked Jemaah Islamiyah terror network.

U.S. officials had offered $5 million for Marwan's capture. The U.S.-trained engineer is believed to have taken part in several deadly bombings in the Philippines.

Umbra Jumdail, head of the Philippine-based Abu Sayyaf militants, and a Singaporean leader in Jemaah Islamiyah were also killed in the attack.

Thursday's strike is the region's biggest anti-terror success in recent years.