A chronology of events in the kidnappings of Martin and Gracia Burnham, and Ediborah Yap:
— May 27, 2001: Gunmen abduct 20 people from a Philippine resort including Martin and Gracia Burnham of Wichita, Kan., and Guillermo Sobero of Corona, Calif.
— May 28: The Abu Sayyaf Muslim extremist group claims responsibility for the abduction in a local radio announcement.
— June 1: Intense gun battle breaks out after rebels take over hospital on southern island of Basilan seize staff, including Filipino nurse Ediborah Yap, and medicine to treat wounded. Four hostages escape as Filipino troops surround hospital and open fire.
— June 3: Rebels under fire from helicopter gunships, ground troops and police escape at night into the jungle, sparking claims that the army accepted bribe money to let them go.
— June 11: Guerrilla leader Abu Sabaya says on radio that the rebels had "chopped the head of Guillermo Sobero." Earlier in the day, the rebels took 15 workers from a local plantation hostage.
— June 16: The military starts arming about 1,000 former and current militiamen belonging to other Muslim separatist groups on Basilan to help hunt the rebels.
— July 6: Residents report seeing Abu Sayyaf guerrillas with their captives in Basilan's mountainous heartland, called Sampinit Complex.
— Dec 3: In a televised interview, the Burnhams, handcuffed and looking tired after six months in southern jungles, say they are increasingly ill.
— Dec 20: The Philippine military receive hundreds of firearms, including high-powered sniper rifles, from the U.S. Army as part of a $100 million aid package in the American global effort to fight terrorism.
— Jan 31, 2002: First U.S. troops arrive as part of a six-month mission to train Filipinos fighting the Abu Sayyaf.
— Feb 15: About 160 U.S. Special Forces arrive on Basilan island.
— Feb 22: A U.S. Army Chinook helicopter participating in anti-terrorism exercises with Philippine troops crashes in the southern Philippines, killing all 10 Americans aboard.
— Apr 25: Paul Burnham, the father of Martin Burnham, calls local radio station to say the Abu Sayyaf reneged on an agreement to release the couple.
— Apr 28: Local radio broadcasts phone call by Abu Sayyaf leader Abu Sabaya, saying his group was open to "last deal" negotiations and denied reports of receiving $300,000 ransom.
— May 1: Abu Sabaya calls radio, threatening to kill the hostages if negotiations are unsuccessful.
— May 20: Brig. Gen. Donald Wurster, head of U.S. troops in the southern Philippines, said the search for the Burnhams turned up no encouraging leads despite U.S. military surveillance since January.
— June 7: Martin Burnham and Ediborah Yap are killed and Gracia Burnham is wounded but rescued in a military raid on an Abu Sayyaf band in the southern province of Zamboanga del Norte.