MANILA, Philippines -- They called the project Bojinka, "the explosion."
The plan was devastating in its complexity and technical brilliance. If it had not been foiled, it might have been the worst terrorist attack in U.S. history.
Project Bojinka was a plan to blow up 11 U.S. airliners over the Pacific in a day of rage at the United States.
According to investigators, it called for five Muslim terrorists to plant virtually undetectable bombs aboard the planes, all jumbo jets, in an intricately synchronized plan that had the bombers changing planes as many as four times in a day.
The U.S. government has accused Ramzi Ahmed Yousef, the Pakistani suspected of engineering the New York World Trade Center bombing, of being the mastermind behind the Bojinka plot.
Mr. Yousef was captured in Pakistan in February and is awaiting trial in New York on charges of planning both attacks. If convicted, he could be sentenced to death.
Also charged in the airliner plot is a Pakistani named Abdul Hakim Murad, 27, who was arrested by police Jan. 6 in an apartment here. Police said they found pipe bombs, bomb-making manuals and a computer with details of the Bojinka plot squirreled away on its hard disk. Mr. Murad was extradited to New York.
Both men have pleaded not guilty.
While the 14-count federal indictment in New York accused the two of conspiring to "set fire to, damage, destroy, disable and wreck aircraft in the special aircraft jurisdiction of the United States," the scope of the plan has never been disclosed.
The two were also accused in the Philippines of planning to assassinate Pope John Paul II while he visited that country in January. That plan is now believed to have been designed to confuse authorities and deflect attention from their plan to blow up the airplanes.
Philippine and Western intelligence experts said in interviews that the investigation into the Bojinka plot has also provided disturbing evidence of the existence of a worldwide network of terrorists who received weapons training and firebrand religious indoctrination during the decade-long international effort to defeat the Soviet Union in Afghanistan.
The international brigades of Afghan "mujahedeen," or resistance fighters, were recruited throughout the Islamic world as part of a covert, $4 billion effort in the 1970s and 1980s by the U.S. Central Intelligence Agency and Saudi Arabia to drive the Soviets from Afghanistan.
Since the Soviet-installed government fell in 1992, many of the fighters have returned to their home countries as converts to radical Islam determined to overthrow secular regimes and attack the "Satan" United States for its support of Israel.
"We believe there is a worldwide organization of Muslims espousing extremism to pursue their religious and political ends," said Alexander P. Aguirre, the Philippines' undersecretary the interior and a former police chief of Manila.
He said no one had yet proved a link between the terrorists and a specific state sponsor.
Philippine officials acknowledge that the thwarting of Project Bojinka owes less to investigative prowess than to an accident ++ that occurred Jan. 6. They allege that Mr, Yousef and Mr. Murad were mixing bomb material in the sink of an apartment in Manila when the mixture suddenly began spewing clouds of smoke.
Police first thought the pope was the prime target; only after Mr. Murad was questioned and the disk on the apartment's computer was decoded did details of the Bojinka plan emerge.
Mr. Yousef eluded a police dragnet, and three days later the U.S. Federal Aviation Administration issued a warning to U.S. airlines operating in Asia to be on maximum alert for a new kind of bomb.
A notebook written in Arabic was among items found in the apartment. "It was like a cookbook with step-by-step instructions on how to make various bombs," said one Philippine official, adding that the FBI later found fingerprints on the notebook. They matched Mr. Yousef's.
Philippine authorities say they have evidence that Mr. Yousef carried out a practice run for the Bojinka plot.
On Dec. 11, 1994, a bomb exploded aboard Philippine Airlines Flight 434 bound for Tokyo. The blast killed a Japanese tourist seated near the explosive, which was taped under a seat in the economy section, and injured 10 others. The plane made an emergency landing in Guam.
Shortly after the incident, authorities say, a man telephoned the Associated Press in Manila and claimed that the attack was the work of the Abu Sayyaf group, a Muslim extremist organization that has been carrying out terrorist attacks in the southern Philippine province of Mindanao for five years.
Mr. Murad told investigators that a jubilant Mr. Yousef had made the call himself as part of a long-term cooperation arrangement between Mr. Yousef and Abu Sayyaf.
An engineering graduate of Britain's Swansea University, Mr. Yousef had created a virtually undetectable bomb.
From the bomb formula found in the computer and evidence provided by Mr. Murad, authorities said, Mr. Yousef had learned to make a stable, liquid form of nitroglycerin, the explosive component of TNT. Liquid bombs are the most difficult to manufacture because of the volatility of the chemicals.
Mr. Yousef, who reportedly wears contact lenses, concealed the nitroglycerin compound in a bottle normally used to hold saline solution for wetting lenses.
Mr. Murad told authorities that after the plane took off, Mr. Yousef locked himself in the restroom and mixed a highly explosive form of nitroglycerin.
He assembled the bomb and later taped the package under the life preserver beneath his seat.
According to Mr. Murad, authorities said, the Philippine Airlines bomb provided the model for the Bojinka plan. Five terrorists, including Mr. Yousef and Mr. Murad, would fan out over Asia, targeting U.S. airlines that flew multistop routes.
In all, the five terrorists would place bombs aboard 11 U.S. planes and meet again later in Karachi, Pakistan.
Although only two of the five alleged bombers have been caught, the other three have tentatively been identified from photographs that were also found on the computer's hard disk, in a file that had been erased.
Mr. Yousef was apparently unaware that such files could be restored.
One of the accomplices has been positively identified as an Afghan named Wali Khan Amin Shah, who had been under surveillance in the Philippines as a possible terrorist. Police believe another of the suspects may have been Mr. Yousef's brother. The fifth accomplice's name was not revealed.
On Monday, the Philippines government acknowledged that it had been given a 90-day ultimatum by the FAA to tighten security at Manila airport or face a U.S. landing prohibition on all aircraft that had traveled to Manila.