MANILA, Philippines -- A bomb planted inside a backpack ripped through an airport terminal in the southern Philippines on Tuesday, killing at least 21 people -- including an American missionary -- and injuring 145 in the nation's worst terrorist attack in three years.
The blast comes at a time of heightened debate over the role of U.S. troops in the war on terror in the Philippines, where Muslim insurgents have battled the government for decades with attacks, bombings and kidnappings.
Three Americans, a Southern Baptist missionary and her two young children, were among the wounded. Two of the 147 who were injured -- many of them in serious condition -- died overnight to bring the death toll to 21. There were no details on the most recent deaths, but the earlier fatalities included a boy, a girl, 10 men and seven women.
President Gloria Macapagal Arroyo, who invited U.S. troops to help train Filipino soldiers in counterterrorism, said the bombing at Davao airport on Mindanao island was "a brazen act of terrorism which shall not go unpunished."
President Bush condemned the attack as a "wanton terrorist act" and sent condolences to the people of the Philippines, his press secretary Ari Fleischer said.
"The president notes that the bombing underscores the seriousness of the terrorist threat in the southern Philippines, and he emphasizes that the Philippines have been a stalwart partner of the United States in the war against terror," Fleischer said.
No one claimed responsibility for the blast, but Arroyo said "several men" were detained. The military has blamed Moro Islamic Liberation Front rebels for a string of attacks, including a car bombing at nearby Cotabato airport last month that killed one man.
U.S. Special Forces are training Philippine soldiers in counterterrorism tactics in the city of Zamboanga, about 250 miles west of the scene of Tuesday's attack.
Eid Kabalu, spokesman for the rebel group, which has been fighting for Muslim self-rule in the predominantly Roman Catholic Philippines for more than three decades, denied his group was responsible. He condemned the attack and said the group was ready to cooperate in an investigation.
Police said the bomb was hidden in a backpack planted in the middle of the airport's waiting area. The blast was heard three miles away; some of the debris landed 100 yards away.
The Southern Baptist Convention's International Mission Board in Richmond, Va., confirmed that missionary William P. Hyde, 59, of Cedar Rapids, Iowa, died in surgery from head and leg injuries.
Hyde had gone to the airport to meet American missionaries Barbara Wallis Stevens and Mark Stevens and their family, who were had just arrived from Manila when the bomb went off.
"I just heard it explode to my side," said Barbara Wallis Stevens, 33, of Willard, Mo., who was slightly wounded. "I was carrying my infant son so I grabbed my daughter and picked her up and ran away."
She said 10-month-old Nathan was hit by shrapnel in the liver. Her daughter, Sarah, was also injured but released after treatment.
Hyde, a former music teacher, had been a missionary since 1978. He and his wife, Lyn, have two grown sons, one of whom is a missionary in Cambodia.
David Miller, pastor of Northbrook Baptist Church in Cedar Rapids, called Hyde "kind of the teddy bear type -- kind, gentle and always smiling."
Miller said the Hydes had been close friends of Martin and Gracia Burnham, American missionaries who were kidnapped in 2001 by another Muslim extremist group, Abu Sayyaf. Martin Burnham was killed during a rescue operation in June 2002, and his wife was wounded.
In a separate incident Tuesday, an explosion in Tagum, about 20 miles north of Davao, injured several people, said a military spokesman, Lt. Col. Daniel Lucero. The military suspected Moro Islamic Liberation Front guerrillas in that attack.