ZAMBOANGA, Philippines ? A top Abu Sayyaf leader linked to the kidnappings of Kansas missionaries and scores of other people was believed to have been killed in a firefight with government troops today, military sources said.

Abu Sabaya was the most visible of the Muslim extremist group’s commanders, often calling up local media with demands and statements taunting the government. The military said it had been hot on his trail after a June 7 rescue of Martin and Gracia Burnham of Wichita, Kan. Martin Burnam and Filipino nurse Ediborah Yap were killed and Gracia Burnham was wounded but freed.

Last year, the rebels celebrated the June 12 country’s Independence Day holiday by presenting the president with what Sabaya called a “gift”: the beheading of hostage Guillermo Sobero, a tourist from Corona, Calif.

Military sources, quoting soldiers and rebel survivors, said a marine and special warfare amphibious group patrolling off Mantibu Point on the main southern island of Mindanao intercepted a boat with armed men around 4:15 a.m. The troops came under fire and shot back.

The five-minute exchange left three suspected Abu Sayyaf rebels dead and four others captured.

A body believed to be that of Sabaya was recovered, sources said, and officials were trying to confirm the identity.

Troops said they had found Sabaya’s trademark sunglasses and backpack at the site of the June 7 clash in the dense jungle of Zamboanga del Norte province on the main southern island of Mindanao. Friday’s gunbattle occurred nearby, and the military sources speculated the rebels may have been trying to flee the island.

Freed hostages have talked about how Sabaya led a pre-dawn raid on an upscale resort on May 27, 2001, in which a band of the guerrillas snatched 20 hostages without firing a shot. Included were the Burnhams and Sobero.

Using speedboats purchased with ransoms from another mass abduction a year earlier, the guerrillas transported the hostages across the Sulu Sea to Basilan island, where the military launched a massive search that eventually would lead to an ongoing six-month deployment of 1,000 American troops to provide training and high-tech support to the badly undertrained and underequipped Philippine troops.

The Abu Sayyaf, with its roots in the region’s Muslim separatist movement and reported early support from the al-Qaida terrorist network, had steadily moved toward becoming a bandit gang, thriving on kidnapping-for-ransom and killing captives whose families couldn’t afford to pay.