Unprecedented Alert at Heathrow

Tanks, armored cars and more than 200 troops surrounded Heathrow Airport yesterday and continued today in an unprecedented alert prompted by reports that Arab terrorists planned to shoot down an airliner with portable Soviet-made ground-to-air missiles. The cordon was partially lifted at nightfall when air traffic is thin but was restored at dawn today. A senior police officer told reporters that the decision to surround the airport with troops was authorized by Home Secretary Robert Carn acting at the request of police.

Particular attention was being paid to the approaches and take-off points where terrorists would have the best chance of hitting low-flying aircraft. Roadblocks were set up near the airport and all passing cars were searched. A Scotland Yard statement described the alert “a joint police-military exercise” which was “part of the contingencies which have been planned to deal with emergencies.” It was anticipated that the alert would last several days.

The alert, unprecedented in peace-time Britain, has been linked to reports that Soviet-made SAM-7 missiles were smuggled into Belgium in the luggage of Libyan diplomats. The missiles were said to be somewhere “on the loose” in Europe. But there was no indication of the nature or source of the warning received by Scotland Yard.

The Heathrow emergency coincided with the arraignment at a magistrate’s court here yesterday of three persons suspected of an arms smuggling attempt on behalf of Arab terrorists. They are Allison Thompson, 18, of Santa Barbara, Calif.; Abdelkebir el-Hakkaoui, 25, a Moroccan; and Ather Naseem, 21, a Pakistani. Their hearing was continued until Jan. 14. All are being held without hail. No connection is known to have been established so far between their alleged activities and the shooting Dec. 30 of J. Edward Sieff.