Libya celebrated the 40th anniversary of the coup that brought Col. Moammar Gadhafi to power with a parade, lavish dance spectacles and fighter jets streaking overhead on Tuesday.

The festivities were designed to show off the former pariah state's acceptance on the world stage after renouncing nuclear weapons and terrorism. But new controversies over the return of the Lockerbie bomber, the detentions of two Swiss businessmen and even the color of smoke emitted by planes at the ceremonies revealed the tenuous nature of Gadhafi's relations with the West.

Gadhafi kicked off the celebrations early Tuesday, timed to coincide with the coup's start, with a feast at a former U.S. air base that was turned into a Libyan military camp. The celebrations are slated to last four days.

A military parade is expected to be held Tuesday afternoon while a large-scale celebration will take place in a Tripoli stadium in the evening after the end of the Ramadan fast.

Ahead of the parade, a large number of uniformed soldiers gathered on a street along the Mediterranean Sea that leads to Tripoli's Green Square, a sweeping plaza decorated with numerous green Libyan flags.

Gadhafi came to power with a military coup in 1969, and was ostracized for decades over accusations of supporting international terrorism, including the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland that killed 270 people.

But more recently, Gadhafi has tried to restore his country's standing in the world and transform it from a pariah state to a member of the international community.

Gadhafi surprised the world by agreeing to dismantle his country's weapons of mass destruction programs. The United States restored ties with Libya in 2006 after Gadhafi agreed to resolve the Lockerbie issue including paying compensation to the victims' families.

The Libyan leader will be making his first visit to the U.S. later this month to address the United Nations in what was expected to be the culmination of years of effort to repair his international image.

But controversy persists in dogging the Libyan leader.

Libya invited many heads of state to the anniversary celebrations, but in a sign of the still touchy relationship many western countries have with Libya and concern over how to treat the Mediterranean country following the Lockerbie bomber's release, many sent lower-level representatives or stayed away.

Scottish officials released the only man convicted of the Lockerbie bombing, Abdel Baset al-Megrahi, on Aug. 20 on compassionate grounds, saying doctors determined he suffered from terminal prostate cancer and had only three months to live.

The bomber's release and warm welcome in Libya met with international outrage from many of the victims' families and U.S. officials.

In New Jersey, which lost dozens of residents on the doomed Pan Am flight, outraged residents protested plans by Gadhafi to pitch a Bedouin-style tent on the grounds of a mansion owned by the Libyan government during his upcoming New York trip.

Libyan representatives said later that he would remain in New York.

Since al-Megrahi's return, he has been hospitalized and his health has quickly gotten worse, said a senior Libya official Tuesday.

Asked how long al-Megrahi could still have to live, Libyan State Information Agency, Majid al-Dursi, said: "Only God knows when it will be over. But he is dying now."

There was no way to independently verify his health, and it was not clear how long al-Megrahi has to live. Television footage on Britain's Channel 4 Sunday showed al-Megrahi in the hospital, breathing through an oxygen mask and propped up by pillows.

The U.K. and Scottish governments on Tuesday made public correspondence on the Lockerbie bomber's release, in response to intense public pressure to justify the decision. A letter from Britain's Foreign Office advised Scottish officials that there were no legal obstacles to al-Megrahi's return to his native Libya, and that Britain had never made a binding promise to the United States to keep the bomber jailed in Scotland.

In another Libyan squabble, Swiss officials said Tuesday that the Mediterranean country broke its promise to free two Swiss businessmen by Sept. 1 who have been held since last summer. The two men were caught up in a spat between Libya and the Alpine nation following the arrest last summer of Gadhafi's son. Geneva police briefly detained Hannibal Gadhafi and his wife in a luxury hotel for allegedly beating up two of their servants.

Libya retaliated in outrage by severing business and diplomatic ties with Switzerland, and detaining the businessmen, allegedly for violating immigration rules.

Even the 40th anniversary celebrations were not without controversy. In a sign of how tightly Libya is trying to control the festivities, Italy said Libya wants an Italian air force acrobatic team flying over Tripoli to only emit green smoke — a color Gadhafi associates with his regime — during its performance.

Italian Premier Silvio Berlusconi said Tuesday that the jets, that usually emit red, white and green colors of the Italian flag, won't fly if Libyan adheres to its green-only demand.

Rome has maintained generally good relations with Gadhafi, and Libya is a major supplier of gas and oil to Italy, Libya's former colonial ruler.

Berlusconi met with Gadhafi in Libya on Sunday to mark the one-year anniversary of a friendship treaty with Tripoli.

Despite Gadhafi's attempts to restore his international reputation, human rights groups say he has failed to grant Libyans greater freedoms and rights. The New York-based Human Rights Watch Monday called on Gadhafi to free political prisoners and remove repressive laws that restrict Libyans' rights and freedoms.