Manila, Philippines ? A Philippine military report released Monday said soldiers used extreme caution on a mission to rescue two Americans and a Filipina nurse held hostage by Muslim extremists, but did not say how two of the captives were killed.

Elite Philippine troops ambushed rebels of the Abu Sayyaf group on June 7 in the southern Philippines. Martin Burnham, a missionary from Wichita, Kan., and Ediborah Yap were killed in the ensuing shootout. Burnham’s wife, Gracia, was shot in the right thigh but rescued.

The report signed by Maj. Gen. Ernesto Carolina, head of military forces in the south, said soldiers used single-shot fire and refrained from using grenades in hopes of sparing the hostages.

The Abu Sayyaf rebels were “firing in all directions” on full automatic, the report said. “Enemy bullets continued to rain … near the American hostages.”

The report said Martin Burnham was shot in the back, but did not say who shot him. It also did not conclude how Yap was killed, but said the rescue “team believed she was hacked by a bladed weapon judging from the gaping wound she sustained.”

Soldiers had said earlier Yap was apparently shot in the back.

Three rebels were killed and seven soldiers were wounded in the fighting. About 20 rebels escaped into the jungle during the shootout.

The Philippine military was to hold a news conference today to further explain the eight-page report.

The Burnhams were kidnapped May 27, 2001, from a southwestern beach resort, along with Guillermo Sobero of Corona, Calif., and 17 Filipinos. Yap was taken hostage five days later during a rebel raid of a southern hospital.

Sobero and some of the hostages were beheaded weeks later. Others escaped or were released, reportedly for ransom.

About 1,000 U.S. troops are involved in a counterterrorism exercise in the southern Philippines to train Filipino soldiers to better fight the Abu Sayyaf.

Philippine military officials have said U.S. surveillance equipment, including spy planes and satellite imagery, was vital in tracking down the Abu Sayyaf guerrillas holding the Burnhams and Yap.