Worldwide Hunt Launched for Bombers of Pan Am Jet : Explosion Blamed in Death of 270

The Pan Am jumbo jet that crashed in a fireball in Scotland a week ago was blown out of the sky by a powerful bomb made of plastic explosives, British authorities announced today, and an international search was launched for the saboteurs.

Pan Am Flight 103 rained down on this small Scottish village, killing all 259 aboard and at least 11 people on the ground, on Dec. 21, an hour after it took off on a flight from London’s Heathrow Airport to John F. Kennedy Airport in New York.

Department of Transport investigators said they found “conclusive evidence of a detonating high explosive” in wreckage recovered from the Scottish countryside.

They said in a statement that the evidence was found on “two parts of the metal luggage pallet framework”--a metal luggage container.

“The explosive’s residues recovered from the debris have been positively identified and are consistent with the use of a high-performance plastic explosive,” the statement said.

The statement gave no further information on the type of explosive, nor did it say where it was hidden or how it got aboard the aircraft. It also did not speculate on who was responsible for the bombing or a possible motive.

President Reagan was informed at his Bel-Air home this morning by National Security Adviser Colin L. Powell, Deputy Press Secretary Leslye Arsht said. The White House pledged “all available resources” to find out who was responsible.

In Washington, the State Department pledged that a “vigorous investigation” will be carried out by the FBI and other U.S. government offices.

“We are doing everything possible and using all available resources and sources to find out who did it,” spokeswoman Phyllis Oakley said. “We are determined to get to the bottom of this and find out who did it.”

“This operation has developed into a criminal inquiry of international dimensions,” said John Boyd, chief constable of the area in Scotland where the crash occurred.

The Transport Ministry statement was distributed to news organizations in London and read to reporters in Lockerbie by Michael Charles, head of the Air Accidents Investigation Branch of the Transport Ministry. Charles declined to answer reporters’ questions after reading the statement.

The statement said evidence collected by the branch, including the cockpit voice and flight data recorders and the trail of wreckage on the ground, “has led to the preliminary conclusion that the explosion took place soon after the aircraft had crossed the Scottish border whilst it was in the cruise at 31,000 feet and that this led directly to its destruction.”

“Much investigative work remains to be done to establish the nature of the explosive device, what it was contained in, its location in the aircraft, and the sequence of events immediately following its detonation,” the statement said.

It said that wreckage, baggage and part of the framework of a metal luggage pallet are being examined by Ministry of Defense scientists and that more items collected by Air Accidents Investigation Branch investigators “will be subjected to lengthy chemical and metallurgical forensic examinations.”