Some initial speculation stated that explosives brought down Flight 394 . Indeed , in December 1988 , a bomb had brought down Pan Am Flight 103 . In addition , Norwegian Prime Minister Gro Harlem Brundtland had used that particular Partnair aircraft on her campaign trips . The Norwegian press believed that the crash was an assassination attempt . Witnesses of the crash said that they heard a loud noise as they saw the aircraft fall . The fact that the aircraft had disintegrated in the air gave credibility to the bomb theory . The speculation in the press later included a scenario where the plane had been shot down , possibly by the NATO war exercise " Operation Sharp Spear , " which took place on the day of the accident flight near the flight path , as investigators had found small traces of high explosives on parts recovered from the sea bed . However , investigators found that the residue was not from a bomb or a warhead , as there was not enough of it present . Finn Heimdal , an AIBN investigator , said in an interview that the residue appeared to be more like a contamination than any other possibility . The sea had old munitions as many battles had been fought off the coast of Denmark . Investigators concluded that the aircraft pieces acquired residue from the bottom of the sea or that the traces of explosives were accumulated from contamination before the accident or due to storage
Pan Am Flight 103
Pan Am Flight 103
Partnair Flight 394