The Boeing 747 en route from London to New York exploded in mid-air over Lockerbie on 21 December 1988.

All 259 people on board were killed along with 11 people on the ground.

Messages from Prime Minister Tony Blair and President Bill Clinton were read as 10th anniversary services proceeded in Lockerbie, London, Washington and Syracuse, the US home of 35 of the dead.

'Establish the truth'

The BBC's Andrew Cassell reports from the rememberance service in Lockerbie

Mr Blair's message, read out in Lockerbie by Scottish Secretary Donald Dewar, recalled "a calamity made and perpetrated by men" which had imprinted itself on the public mind.

It read: "Today, as we remember those who died and those who mourn, we renew our resolve to establish the truth and to ensure that justice is done."

The small Scottish town was devastated

President Clinton said the US would consider tougher sanctions on Libya, which has refused to hand over two men suspected of the bombing, at a UN review next February.

His message read: "This cowardly act of terrorism outraged not only the people of the United States and Great Britain, but also civilised men and women everywhere."

President Clinton paid tribute to relatives and Lockerbie towns people who turned sorrow into "a source of strength for all who stand against terror".

He said: "We mark this milestone at the time of the time of the winter solstice, when the sun begins to reclaim the day.

"It is a fitting moment to note your extraordinary determination to bring light forth from this tragedy."

The Queen also sent her message. It read: "Our thoughts and prayers today are with the families and friends of those 270 people, from so many countries, whose lives were tragically taken in the Lockerbie bombing 10 years ago.

The Duke meets mourners at Lockerbie

"Time cannot erase their memory."

In separate events, British relatives gathered for a service in Westminster Abbey. Americans came together at Arlington national cemetery in Washington where President Clinton was present, and many more gathered at Syracuse University.

One-minute silence

All services held a one minute silence at 1900 GMT, the moment the Jumbo jet was destroyed by a bomb six miles above the Scottish town.

At Westminster Abbey, the names of all 270 victims were read out and a candle lit in their memory.

Jane Swire's prayer at Westminster Abbey for those who "were torn from this temporal world by a terrorist bomb"

Jane Swire, whose daughter was killed in the tragedy, read a prayer to the congregation. She said families and friends continued to mourn "individuals torn from a temporal world by a terrorist bomb to join the eternal world far, far sooner than fullness of life would warrant".

In the afternoon, the Duke of Edinburgh had laid a wreath at the memorial stone to the victims at the local cemetery at Lockerbie on behalf of the Queen.

Father Patrick Keegans, who was at based in Lockerbie at the time, delivered a powerful expression of the complex emotions of both the relatives and the locals.

"You will see us laying wreaths at your stone," he said addressing the dead and the living. "We want you to be sure that these wreaths are not hollow empty gestures but a statement and declaration full of promise.

"Ten years ago, for you and for us, a bomb was ticking.

"Know this, there is another bomb ticking, the irresistible bomb of justice and truth."

As the two countries remember their dead, negotiations to bring two Libyan suspects continue apace. Libya's leader Colonel Gaddafi offered some hope to those who want to see justice by telling Dutch TV that the trial should take place in an international court.

Diplomats and campaigners for the relatives of the victims believe a trial with Scottish judges and under Scottish law will take place as early as January at the Hague in the Netherlands.

But UK Foreign Secretary Robin Cook has insisted that if convicted the two men would have to be imprisoned in Scotland.