Despite the warning, thousands of young men were on hand at the military airport in Tripoli where al-Megrahi's plane touched down. Looking tired and wearing a dark suit and a burgundy tie, al-Megrahi left the plane.
He was accompanied by Libyan leader Moammar Gadhafi's son, Saif al-Islam Gadhafi, who was dressed in a traditional white robe and golden embroidered vest. The son pledged last year to bring al-Megrahi home and raised his hand victoriously to the crowd as he exited the plane. They then sped off in a convoy of white sedans.
But al-Megrahi's release disgusted many victims' relatives.
"You get that lump in your throat and you feel like you're going to throw up," said Norma Maslowski, of Haddonfield, N.J., whose 30-year-old daughter, Diane, died in the attack.
"This isn't about compassionate release. This is part of give-Gadhafi-what-he-wants-so-we-can-have-the-oil," said Susan Cohen, of Cape May Court House, N.J. Her 20-year-old daughter, Theodora, was killed.
At home, al-Megrahi, 57, is seen as an innocent scapegoat the West used to turn this African nation into a pariah. At the airport, some wore T-shirts with his picture and waved Libyan and miniature blue-and-white Scottish flags. Libyan songs blared in the background.
"It's a great day for us," 24-year-old Abdel-Aal Mansour said. "He belongs here, at home."
Moammar Gadhafi lobbied hard for the return of al-Megrahi, an issue which took on an added sense of urgency when al-Megrahi was diagnosed with prostate cancer last year. He was recently given only months to live.
The former Libyan intelligence officer was convicted in 2001 of taking part in the bombing on Dec. 21, 1988, and sentenced to life in prison for Britain's deadliest terrorist attack. The airliner exploded over Scotland and all 259 people aboard and 11 on the ground died when it crashed into the town of Lockerbie.
Al-Megrahi's conviction was largely based on the testimony of a shopkeeper who identified him as having bought a man's shirt in his store in Malta. Scraps of the garment were later found wrapped around a timing device discovered in the wreckage of the airliner. Critics of al-Megrahi's conviction question the reliability of the store owner's evidence.
He was sentenced to serve a minimum of 27 years in a Scottish prison. But a 2007 review of his case found grounds for an appeal, and many in Britain believe he is innocent. He served only eight years.
Scottish Justice Secretary Kenny MacAskill said although al-Megrahi had not shown compassion to his victims - many of whom were American college students flying home to New York for Christmas - MacAskill was motivated by Scottish values to show mercy.
"Some hurts can never heal, some scars can never fade," MacAskill said. "Those who have been bereaved cannot be expected to forget, let alone forgive ... However, Mr. al-Megrahi now faces a sentence imposed by a higher power."
He added that he had ruled out sending the bomber back to Libya under a prisoner-transfer agreement, saying the U.S. victims had been given assurances that al-Megrahi would serve out his sentence in Scotland.
"I don't understand how the Scots can show compassion," said Kara Weipz, of Mount Laurel, N.J. Her 20-year-old brother Richard Monetti was on board the doomed flight. "I don't show compassion for someone who showed no remorse."
As al-Megrahi's white van rolled down street outside Greenock Prison on his way to the airport in Glasgow, Scotland, some men on the roadside made obscene gestures. He later appeared on the airport tarmac dressed in a white tracksuit and baseball cap.
In a statement following his release, al-Megrahi stood by his insistence that he was wrongfully convicted.
"I say in the clearest possible terms, which I hope every person in every land will hear - all of this I have had to endure for something that I did not do," he said.
He also said he believed the truth behind the Lockerbie bombing may now never be known.
"I had most to gain and nothing to lose about the whole truth coming out - until my diagnosis of cancer," he said, referring to an appeal that he dropped in order to be freed. "To those victims' relatives who can bear to hear me say this, they continue to have my sincere sympathy for the unimaginable loss that they have suffered."
Gadhafi engineered a rapprochement with his former critics following the Sept. 11, 2001, terrorist attacks. He renounced terrorism, dismantled Libya's secret nuclear program, accepted his government's responsibility for the Lockerbie bombing and paid compensation to the victims' families.
Western energy companies - including Britain's BP PLC - have moved into Libya in an effort to tap the country's vast oil and gas wealth.
Briton Jim Swire, whose daughter Flora died on Flight 103, welcomed the Libyan's release, saying many questions remained about what led to the bomb that exploded in the cargo hold.
"I think he should be able to go straight home to his family and spend his last days there," Swire told the BBC. "I don't believe for a moment this man was involved in the way he was found to be involved."
Among the Lockerbie victims was John Mulroy, the AP's director of international communication, who died along with five members of his family.
Associated Press Writers Geoff Mulvihill in Mount Laurel, N.J., Shawn Marsh in Trenton, N.J., Meera Selva in London, Matthew Lee in Washington, Jessica M. Pasko in Albany, N.Y., and Jim Hannah in Dayton, Ohio, contributed to this report.