AT 7.03PM ON 21 December 1988, a bomb exploded on Pan Am Flight 103, killing all 243 passengers and 16 crew on board.

The aircraft then crashed into the town of Lockerbie in Scotland. Eleven more people were killed on the ground.

Twenty-five years on, events are being held in the UK and US today to remember and honour the 270 victims.

A wreath-laying ceremony is to take place at Dryfesdale Cemetery with Scotland’s First Minister Alex Salmond in attendance. Westminster Abbey, Arlington National Cemetery in Virginia and Syracuse University also organised memorials.

“Lockerbie remains one of the worst aviation disasters in history and the deadliest act of terrorism ever committed in the United Kingdom,” British Prime Minister David Cameron said as he marked the anniversary of the tragedy.

The loss of the flight was a shocking event that was “made more poignant still by being so close to Christmas”, he added.

“Over the last quarter of a century much attention has been focused on the perpetrators of the atrocity. Today our thoughts turn to its victims and to those whose lives have been touched and changed by what happened at Lockerbie that night.

“To families, friends, neighbours, loved ones, and all those caught up in the painful process of recovery. Let us say to them: our admiration for you is unconditional. For the fortitude and resilience you have shown. For your determination never to give up. You have shown that terrorist acts cannot crush the human spirit. That is why terrorism will never prevail.

And even in the darkest moments of grief, it is possible to glimpse the flickering flame of hope.

The majority of the passengers on board were American citizens, including 35 students from Syracuse University.

Cameron noted that there is still a strong bond between the Scottish town and the school.

“Syracuse lost 35 of its own on that fateful evening. Nothing can restore the promise of those young lives cut short. Yet their memory is honoured by the scholarships Syracuse awards each year to 2 Lockerbie students and 35 of its own undergraduates,” he said.

“They represent a growing band of beneficiaries, each given the chance to fulfil their own youthful promise. This is the lasting and optimistic legacy bequeathed to future generations on behalf of those who lost their lives on this day 25 years ago and who we remember here today.”