[What follows is the text of a report issued by The Associated Press news agency on this date in 1989:]
The government yesterday tightened security procedures for airport workers after two journalists posing as cleaners exposed major lapses at London's Heathrow Airport after the bombing of Pan Am Flight 103.
Earlier, the Sunday Post newspaper in Scotland quoted a former high-ranking Israeli intelligence agent as saying he believes Abu Ibrahim, head of a Palestinian group, planned the Dec 21 bombing, which killed 270 people.
ABC News, citing unidentified US and Western intelligence sources, reported yesterday that several dozen intelligence agents from the Palestine Liberation Organization are working with Pan Am on the investigation of the bombing. PLO leader Yasser Arafat had pledged his group's help in the investigation, and ABC quoted its sources as saying the PLO's help has been exceedingly valuable.
Transport Secretary Paul Channon said passes will be issued only to airport employees or to outside companies "which the airport manager is satisfied are reliable and reputable."
"Clearly, some of the firms in this field in the past have been far from reliable," he said in a statement.
Channon said cleaners and other airport workers now will have to have held security passes for at least six months before being allowed unsupervised access to aircraft and checked-in baggage.
He also praised the "swift action" of the British Airports Authority in withdrawing access to airplanes from two privately owned cleaning companies at Heathrow. Graham Dudman of the Daily Express and Stewart Norris of London Weekend Television, working independently, told Friday how they got jobs as airplane cleaners at Heathrow using fake applications.
They said that with passes issued by the two cleaning companies involved, they were able to wander on and off a dozen jets where they said they could easily have planted a bomb.
New York-bound Flight 103 was destroyed by a bomb over the Scottish village of Lockerbie, killing 259 people on the plane and 11 on the ground.
The flight originated in Frankfurt, West Germany, and baggage and passengers were transferred to the Boeing 747 at Heathrow.
In Glasgow, the Sunday Post newspaper quoted former Mossad officer Raphael Eitan as saving he had "no doubt" the bombers were Ibrahim's May 15 Palestinian group, based in Baghdad, Iraq, and that the bomb was made there and probably carried on board the plane by an unwitting accomplice.
"They are led by Abu Ibrahim, a qualified engineer. In the early days Ibrahim received all his financial support from Iraqi intelligence, who continue to provide him with cash and premises," Eitan was quoted as saying.