U.S. Attorney General Eric Holder and other officials are expected to speak at a 25th anniversary memorial service for victims of the 1988 Pan Am airliner bombing over Scotland.


The memorial ceremony is scheduled for Saturday afternoon at Arlington National Cemetery.


Pan Am 103 exploded over Lockerbie, Scotland, on Dec. 21, 1988, soon after takeoff from London.


The terror attack killed 270 people either aboard the plane or on the ground. Many of the victims were American college students flying home for Christmas.


The only man convicted in the bombing, former Libyan intelligence official Abdel Baset al-Megrahi, died of cancer last year. Scottish authorities released him on humanitarian grounds, to the outrage of victims' relatives.