Chronology of Abu Sayyaf hostage crisis

A chronology of the Abu Sayyaf hostage crisis in the southern Philippines which enters its second year today:

An American couple and a Filipino nurse are the last of several batches of captives seized from May 27 last year.

May 27, 2001: Abu Sayyaf gunmen raid the Dos Palmas island resort, seize 20 hostages including US missionary couple Martin and Gracia Burnham from Kansas and Peru-born Californian Guillermo Sobero, and flee by boat to their Basilan island stronghold.

President Arroyo rules out ransom and orders the military to rescue the captives.

June 2: The Abu Sayyaf takes over a hospital in Lamitan, Basilan, abducting medical staff, one of them nurse Deborah Yap. Nine of the original captives escape, but two others are killed as the rebels break out of a military cordon.

June 7: Abu Sayyaf spokesman Abu Sabaya threatens to behead the American captives unless Malaysian negotiators are brought in. Mrs. Arroyo rejects the demand.

June 11: Fifteen more Filipinos are kidnapped in Basilan.

June 12: Abu Sabaya announces his group has beheaded Sobero and later peddles video footage of the American’s supposed execution, but gets no takers.

June 29: Mrs. Arroyo announces she has formally asked the US government to help track down the Abu Sayyaf.

July 13: At least 100 suspected sympathizers of Abu Sayyaf kidnappers are arrested in a major crackdown.

Aug 3: Thirty-five Filipinos are abducted in Basilan. Ten are beheaded, while the rest escape or are released later, giving the kidnappers more mobility and allowing them to stay a step ahead of 5,000 military pursuers.

Aug 24: Congress investigates allegations by Basilan priest Cirilo Nacorda that certain military officials colluded with the Abu Sayyaf to allow their escape from the hospital siege. The probe ends inconclusively.

Sept. 24: US President George W. Bush seeks a global freeze of Abu Sayyaf assets, putting the rebel group on a blacklist with links to Osama bin Laden, the main suspect in the Sept. 11 terrorist attacks in the United States.

Oct. 5: Skeletal remains are found on Basilan. US forensics experts later confirm they are those of US hostage Sobero.

Nov. 20: At a meeting with Mrs. Arroyo in Washington, Bush offers to send US troops to help fight the Abu Sayyaf. She accepts equipment and training assistance.

Dec. 7: Sen. Panfilo Lacson says he launched a secret but unsuccessful effort in Malaysia to broker the release of the hostages. The military later threatens to arrest unauthorized hostage negotiators.

Jan. 10: US military advisers arrive in the South for a six-month anti-terrorist campaign. The US force builds up to about 1,000 including 160 Special Forces troops and 340 navy engineers and their Marine bodyguards on Basilan.

March 7: Local television airs video footage of the Burnhams, reading out an Abu Sayyaf statement in front of three hooded gunmen.

April 25: Martin Burnham’s father reveals the Abu Sayyaf reneged on a secret deal in March to free the US couple. The Abu Sayyaf insists the family had dealt with the wrong party, while both the US and Philippine governments deny ransom had been paid.

May 1: Kidnappers call off hostage negotiations and threaten to kill the American captives if rescuers get too close.

May 9: Martin Burnham is reported suffering from malaria as the government says reports that Gracia Burnham is also ill are "reliable."