It is the late afternoon of a festive Monday when, at the 16 of Princes Gate, home of the Iranian embassy in London, some explosions and the crackling of the automatic weapons mark the culmination of a siege that held in suspense, for six days, the British government, security forces and public opinion.
For a moment it is feared that the terrorists, barricaded inside, decide to blow up the embassy, slaughtering all the hostages (26 people). However, a few moments later, on the balcony of the house next to it, dark shapes appear, making their way with explosive charges through an embassy window.
The men - dressed completely in black - are introduced inside through a cloud of thick black smoke. For the curious, crowded up front, is the first (and probably the last) time when they see in action the 22 ° Regiment of the Special Air Service (SAS).
The way to deal with the siege of armed men with hostages can never be established by a manual. By chance, on the other hand, hundreds of variables must be evaluated: who are the terrorists; what they want; what supports they have; of which armament they are endowed; and above all, what probabilities exist that the hostages are killed, if their requests are not accepted.
In many cases, the security forces choose the line of negotiations, according to procedures that have been tested for years. The hypothesis of a frontal assault is always taken into account, however in recent years the security forces have been induced to caution from the memory of the massacre that took place during the Munich Olympics in the 1972. On that occasion the police of the Federal Republic of Germany attacked the terrorists on the airport runway, but the price of the operation was the death of all the hostages - nine Israeli athletes - killed by their Palestinian kidnappers with hand grenades.
The British police now have a great deal of experience in dealing with terrorist groups. The siege of the Italian restaurant Spaghetti House in the 1975, for example, it ended without bloodshed; and shortly thereafter, an IRA terrorist commando surrendered to a Balcombe Street apartment, doing no harm to the old married couple who had taken hostage. In the siege of Balcombe Street it is thought that the terrorists were induced to surrender from the news, released by the BBC, of an imminent intervention by the SAS.
At Pinces Gate, however, the situation is much more complex and infinitely more dangerous.
At 11.32 on Wednesday, 30 on April, a group of unidentified gunmen had broken into the Iranian embassy, after having smashed the exterior glass doors.
On the five floors of the building, in addition to the nineteen embassy officials, there were also seven strangers, including two BBC operators and policeman Trevor Lock, seconded on the spot by the Scotland Yard Diplomatic Protection Group. Police cars arrived at the scene within minutes, as Agent Lock managed to sound the alarm in Scotland Yard before he was overwhelmed. A little later some specialized departments also arrived: the D 11 - made up of police sharpshooters - who took up positions around the building; the C 13, counter-terrorism department and the men of the technical support department, the C 7. The latter are electronic technical experts, with equipment designed to monitor what was happening inside the embassy.
The Special Air Service operators arrived mid-afternoon, in plain clothes and with the utmost discretion.
The police received the first requests from the terrorists to the 14.30s by telephone, when the embassy was completely surrounded by now.
The terrorists qualified as Martyrs' groups. They claimed to be enemies of the Islamic revolution of Ayatollah Khomeini and in the struggle for the liberation of Khũzestãn, a rich southwestern oil district of Iran, populated by Arabs, already the scene of numerous revolts against Iranian domination.
Their demands included the release of 91 Arab prisoners in Iran and their relocation to London, urging the embassies of Arab states to exercise mediation work with the British authorities.
The ultimatum would expire at 12 the following day: if the requests were not accepted, the terrorists threatened to kill the hostages and blow up the embassy.
At the so-called Zulu check - the police command placed a short distance from Princes Gate - they began to evaluate the various aspects of the situation.
In the sieges of the Spaghetti House (photo) and of Balcombe Street, the terrorists' background proved to be precious to wear off their resistance. The Martyrs Groupinstead, it was unknown.
Negotiations began almost immediately and the authorities, given the situation, decided to proceed with the utmost caution. However, SAS operators are already preparing to intervene. In fact, in the Regent's Park barracks a scale model of the embassy is constructed, in order to allow the familiarization of the men with the building plan, in the event that the failure of the negotiations makes a surprise attack necessary.
The SAS has long been ready for emergencies of this kind. In fact, since the beginning of the 70 years, its training procedures have focused on the counter-revolutionary war and on the fight against international terrorism. The Munich massacre had demonstrated the need for perfectly trained departments ready to intervene anywhere on the planet, at very short notice. Among the planned emergencies - in addition to the diversions of aircraft, ships and trains - there is of course the case of the occupation of buildings with hostage capture.
An area for training at the CQB was built at the SAS Headquarters of Bradbury Lines (Hereford) (Close Quarter Battle), or in close combat with light weapons in a closed environment. The SAS operators have been so trained to break into a room, immediately recognize the targets and shoot them down, without giving them time to react.
The speed of reflexes and the ability to shoot with maximum precision, while rolling on the floor, are in fact the main factors of success in this type of operation. Before going into action, however, you need to get to the room where the hostages are held. This is why training also involves climbing - like in high mountains - and practicing in the use of explosives, to open gates.
During the operation Nimrod - code name of the attack on the Iranian embassy - plastic charges are used to crush the bulletproof glass of the windows. The explosive, packed in sheets, is made to adhere to the glass to blow up the entire window; then flash-bang hand bombs are launched inside (this type of grenades produces only a blinding flash and a deafening roar). The SAS operators have to intervene a moment after the explosion, when the terrorists are still blinded by lightning and stunned by the din.
At Princes Gate, to facilitate the attack, Scotland Yard's C 7 installs numerous microphones in chimneys and embassy walls, so as to locate the precise positions of the terrorists. To cover the noise of the installation, excavations are arranged in an adjacent street, suggesting that the gas company has been called to repair an escape from the pipelines.
Discreetly, a gap is also opened in the dividing wall between the embassy and a house next to it. The bricks are removed one by one, silently, leaving only a thin layer of plaster intact, to then break out of surprise at the last moment.
The police had obtained the release of some hostages in exchange for food and cigarettes; two ultimatums had expired without incident. On the evening of the 1 May Day - second day of the siege - the terrorists had dropped the request for the release of the 91 prisoners, hoping that the mediation of the Arab states could make them get a safe-conduct to leave Iran.
On the morning of the sixth day, Monday 5 May, the situation worsened abruptly: the Government had decided to avoid any new concession and the police had exhausted its bargaining margins, while the terrorists were becoming more and more nervous.
Inside the building the tension begins to rise. The terrorists are now pessimistic about their chances of escape and a heated political debate with some Iranian hostages, the night before, had caused a catastrophe.
At the 11.40, Lock Agent faces a window to let the terrorists start killing the hostages, if good news about Arab mediation did not arrive soon. To save time the police persuade the terrorists to wait until the BBC bulletin at midday: but the news is not very reassuring and at the 13.31, three shots are heard inside the embassy.
At this point the surrender has now become the only way out for terrorists: instead, their conditions are confirmed, and at the 18.50 you hear another three shots.
A few minutes later the door of the embassy is opened and the body of a press officer is unloaded on the sidewalk.
All that remains is to intervene. The police contact the head of the terrorists again, offering him a safe-conduct and a plane to take his men out of Britain. The discussion on the details of bus transport to the airport, however, has the sole purpose of making possible the exact location of the command within the building.
The SAS team goes into action at 19.23. With his face covered in gas masks, His Majesty's special forces men attack the embassy on three sides.
Two operators reach the back terrace, descending from the roof with ropes, but they can not detonate the plastic charges, as one of their mates has become entangled in the ropes just above the windows.
Two other operators descend to the rear balcony on the first floor and open the way with the explosive through the bulletproof glass. A flash-bang grenade is launched and members of the SAS head for the telex room on the second floor, where they know - thanks to the information provided by the men of the 7 C - that many hostages are kept.
The head of the terrorists is on the first floor landing, together with Agent Lock; when he sees an SAS operator framed in the window, he raises his weapon to shoot. Lock, however, throws himself on him, thus giving the two special forces members access to the building.
Meanwhile, other SAS men open their way through the front balcony windows of the first floor, in full view of the cameras. A hand grenade is thrown inside and a few moments later, through the thick blanket of smoke, one of the hostages, the BBC operator Sim Harris, appears unharmed.
At the same time a third team raids inside the embassy, after breaking through the thin layer of plaster in the wall. In a rush, SAS operators head for the telex room. The sentry guarding the hostages opens fire by killing one member of the team and injuring two others.
When the SAS men subsequently enter the room, the watchman and two other terrorists mingled between the hostages, lying on the floor.
The telex room is full of smoke and the real sequence of events has never been established with certainty. The official version of the SAS only speaks of a shooting. Some hostages, however, claimed that the terrorists tried to surrender before the SAS operators opened fire.
After the attack, the bodies of five terrorists are brought out, out of six. Two are found in the telex room, one in a back office, one on the first floor, and the last one in the atrium, near the entrance door. All were shot dead in the chest and head. One of the hostages was shot dead by terrorists during the final fire fight.
The SAS men immediately abandon the theater of their action, in two closed vans.
The siege represented the public debut for the Special Air Service. The negotiations initiated by the police served to avoid the massacre of the hostages, but they were the special forces men who physically liberated them, with a lightning action lasting only a total of 17 minutes.
The Princes Gate operation was conducted with almost surgical precision, and although one of the hostages was killed in the final shooting, there was evidence that the anti-terrorism techniques developed by the SAS operators are effective.
(photo: web / film frames "6 Days")