WASHINGTON--The two Libyan men charged with mass murder in the bombing of Pan Am Flight 103 pleaded not guilty May 3 in a special Scottish courtroom in the Netherlands, while family members of some of the 270 victims of the crash charged that the U.S. and British governments may have conspired to set up the two men as political fall guys.

After more than 11 years since the airplane crashed over Lockerbie, Scotland, prosecutors promised the three-judge panel hearing the case they would call more than 1,000 witnesses in their effort to describe how one of the most extensive criminal investigations in history led to the two men. The trial may take as long as a year to conclude.

When the two defendants--Abdel Basset Ali Megrahi and Lamen Khalifa Fhimah--were asked in English if they were ready for trial, each replied in Arabic, "God, the Beneficent and Merciful, be tolerant. Yes, I am."

The indictment charges that the defendants were intelligence agents for Libyan leader Muammar Gadhafi, and that they used well known Libyan time-bomb techniques to detonate a pound of plastic explosives that had been smuggled aboard the Boeing 747 that was carrying 180 Americans and others headed to New York, just before Christmas 1988. The explosion killed all 259 passengers and crew members on board and 11 people on the ground as the flaming debris fell into the village and surrounding farms.

Col. Gadhafi has promised to accept the judgment of the court, but he warned that further investigations into the actions of Libyan officials or himself would prove fruitless. Speaking before the trial got underway, Col. Gadhafi expressed sympathy for the relatives of the victims and said he had "no connection" with the action and had no idea who the perpetrators were.

"I am sympathetic to all the relatives of all these victims and I pray for them," Col. Gadhafi told BBC news. "I have confidence that the problems of Lockerbie will come to an end and will be finished so that we will be turning over a chapter which has been with us ever since the Cold War.

"All parties have agreed to accept the rule of the law, the rule of the court. If you go further than that we shall come to an endless chain," he continued, suggesting that the U.S. has committed "grisly" crimes which could have motivated any of a number of people seeking revenge to carry out the attack.

The U.S. shot down an Iranian passenger airliner before the Lockerbie disaster, Col. Gadhafi pointed out, adding: "Those people who were killed by America, they have their own families and relatives. They may take revenge. This does not mean that Iran as a state or the Iranian Government is convicted or condemned."

Defense attorneys told the court that they will use what is known in Scottish law as a "special defense"--that is, blaming somebody else for the crime. They said they will specifically accuse two Syrian-based groups, the Palestinian Popular Struggle Front and the Popular Front for the Liberation of Palestine-General Command.

Defense lawyers accused nine alleged members of the two groups, including a man--one of the first suspects identified by investigators but who never was arrested for the PanAm bombing--who is now imprisoned in Sweden for detonating bombs in Stockholm and who is now listed as a prosecution witness.

In the early phases of the investigation, U.S. and British authorities focused on the two Palestinian groups, who they said had the means to carry out the bombing, working with Iranians, who they felt had the motive.

"They (the defense) don�t have to prove that someone else did it," Prof. John Grant of the University of Glasgow Law School said in a published report. "But they can use this to raise doubt and that may be enough for a verdict of �not proven,� which is the legal equivalent of an acquittal under Scots law."

Other legal observers who have followed the investigation over the past decade also warn there are holes in the prosecution�s case against the two men. "I think most Americans just assume that since these two Libyans were indicted, the prosecutors have a cast-iron case," said Robert Black, a law professor at Edinburgh University who has worked with Libya, the U.S. and Britain on the case. "But some of the evidence is less clear-cut than it once appeared to be. Some of the witnesses are backtracking."

Among the most troubling breakdowns in the evidence to be offered by the prosecution is Swiss electronics manufacturer Edwin Bollier, who recently recanted his identification of two fragments of an electronic circuit board which he told investigators nine years ago were parts of a timer he sold to the Libyan government. The man now says the fragments "were never part of our electronic equipment," according to a published report.

Another potential problem for the prosecution is that a former FBI agent who argued most vociferously for the link between the Swiss electronics firm and the Libyans, as opposed to the Palestinian-Iranian connection, was later charged with manipulating evidence in other cases to favor prosecutors.

As a result of allegations against the suspects, Libya has suffered nine years of recently suspended U.S.-sponsored United Nations sanctions--including the revocation of international air travel rights to and from Libya. Meanwhile, some family members of the American victims charge the U.S.-government with last-minute betrayal because they feel Col. Gadhafi is being let off the hook.

"We feel that our government, because of (a letter from U.N. Secretary General) Kofi Annan to (Libyan leader) Gadhafi, has agreed to prohibit the prosecutors from going after Col. Gadhafi," George Williams, president of Victims of Pan Am Flight 103 told reporters April 25. They believe that higher-ups in the Libyan government actually ordered the destruction of the American plane.

Before the trial got underway, the family members worked actively in the United States to achieve several objectives, including: holding the Libyan government responsible for the crash; an investigation of U.S. officials including Secretary of State Madeline Albright for obstructing justice in this case; a complete disclosure of documents related to the terms of the trial itself and the development of changes in the U.S. policy towards Libya; and use of the full force of international law against Libya.

Mr. Williams called it "unconscionable" for Secretary Albright to send special envoys to Tripoli "just three weeks before this trial was to start" to determine whether flights by U.S. aircraft should be permitted into the country once again. Those investigators remained in the country for just one day before they returned to the U.S., he said.