Updated

Senior British politicians and some of the families of those who died in the 1988 airliner bombing over Scotland will gather in London and Scotland for memorials marking the attack's 25th anniversary.

Scottish leader Alex Salmond will lead a wreath-laying ceremony at Dryfesdale Cemetery in the town of Lockerbie, where Pan Am 103 exploded soon after takeoff from London on the evening of Dec. 21, 1988. The terror attack, the deadliest to have taken place in Britain, killed 270.

Later Saturday, other senior Scottish officials will attend a service at London's Westminster Abbey.

In the United States, where most of the victims were from. U.S. Attorney General Eric Holder and other officials will speak at a ceremony at Virginia's Arlington National Cemetery.