Five days later, the shadowy Babak Khoramdin Organisation, named after an 8th-century hero who might best be described as the Iranian Robin Hood, issued a communique claiming responsibility. Describing the proceeds of the robbery as a 'loan' from the state which would be repaid once democracy was established, the BKO added, in true Robin Hood style, that half the cash would be distributed among impoverished flood victims in south Tehran.
It was the latest statement from the organisation since it emerged last summer to claim its first attack against the leadership of the Islamic Republic. In the meantime the BKO has claimed responsibility for an assassination attempt on President Ali Akbar Hashemi Rafsanjani, an explosion at the home of the Iranian spiritual leader, Ali Khamenei, and a bomb at the Intelligence Ministry.
Such has been the anonymity of the organisation that both the regime and its opponents have gone as far as to deny its existence. The Iraqi-based People's Mujahedin organisation, which regards itself as the only viable opposition to the Tehran regime, says the BKO is a fiction. 'They claim operations which didn't happen and from our sources in Iran we know this group does not exist,' the Mujahedins' London spokeswoman, Mariam Moussavi, said yesterday. Pro-regime newspapers have dismissed BKO statements as part of a 'fax war' mounted by ineffectual ex-monarchists.
But this week the BKO surfaced in a west European city and gave its first face-to-face interview to outline its background, objectives and structure. What emerged in eight hours of discussions with the Independent was that, if the BKO is what it says it is, then it has infiltrated the highest echelons of Iran's armed forces, Revolutionary Guard Corps and intelligence services.
By its own account, the BKO's military wing, which it hinted may number fewer than 100 men, is made up entirely of frontline veterans of the Iran- Iraq war - children of the 1979 Islamic Revolution, now in their thirties and forties, who became disillusioned with the course of the revolution during that bloody conflict. Out of a comradeship born in the trenches, a number of regular army and Revolutionary Guard officers are said to have resolved in 1988 to take up arms against the regime once the time was right. The first four years, according to a BKO spokesman, were spent establishing a cell structure and a military-civilian central command - 'more than five people and less than 10'. 'The BKO is a very small circle; a drop in the ocean. But it has chosen its personnel in important places.'
Its first operation was last summer when a BKO commando squad took over a security post in the Tehran suburb of Tajrish and raised the Iranian flag. The attack led to six hours of clashes with Revolutionary Guard reinforcements. In February, it claimed to have mounted an unsuccessful bid to kill Mr Rafsanjani, acknowledging that five of its commandos died and three were captured in the attempt. Details of the attack have been confirmed by independent eyewitnesses.
Last month, the BKO claimed to have bombed the home of Ayatollah Khamenei. 'We exaggerated the incident for propaganda purposes,' the BKO spokesman admitted this week. 'After the attack on Rafsanajani, there were those who said it was part of a power struggle in the regime and that we were agents of the intelligence services. We had to do something to prove ourselves. One of our people, a brother of the Iranian ambassador in Germany, was in Khamenei's house. He opened a gas tap and blew the place up. It was a limited explosion. Like a cat, he'd lost eight lives in the war. This time he died.'
From the text of its communiques and from this week's interview, it is clear that the BKO is ultra-nationalist, secular and republican and that it has no illusions about its chances of overthrowing the regime - 'Such an idea is just a joke,' the spokesman said.
Despite the fact that Babak Khoramdin fought against the Arab invasion of Iran and the Persian kings who had embraced Islam, the organisation that bears his name insists it is not anti-Islamic. Its present strategy is to establish itself in the minds of the Iranian public as a group which will strike back at the regime in response to state repression. 'We want to make the Iranian leaders understand that when they shoot at people demonstrating about the state of the economy that they cannot shoot with impunity,' the BKO spokesman said. 'We will retaliate and they will have to think twice. They have got to understand that there is now someone to shoot back.'
The BKO's ideology favours a strong Iran - 'a regional superpower but not a world superpower as the late Shah wanted'. It claims Iran is currently engaged on long-range missile and nuclear weapons programmes which will invite retaliation from the West. 'The regime is guiding us to where Iraq is now,' the spokesman said. 'It is on the brink of having a nuclear capability and, with its fanatic way of thinking, one of them will eventually use it. We would have the same destiny as Iraq.'
According to the BKO, its attacks have led the regime to increase security and mount investigations to root out the dissidents. The spokesman said that the Intelligence Ministry reported two weeks ago that its department was clean. Three days later, according to the BKO, a small bomb exploded on the third floor of a ministry building in the Saltanatabad district where secret reports are decoded. 'We wanted to show them they're not clean yet.'
If, indeed, the BKO does not exist, then its enemies have done their best to invent it. Forged statements have been issued in the BKO's name (unconscious Islamic references point to them not being genuine) and have then been quoted in the Tehran press in an attempt to prove that the group is a fake; the Israeli intelligence agency, Mossad, has been making discreet inquiries among Iranian exiles to try to find out who is behind the movement; the People's Mujahedin has mounted a big propaganda effort to prove that there is no such thing as the BKO. Whether it involves one man with a fax machine or an elite group of officers at the heart of the regime, the ghost of Babak Khoramdin has at least succeeded in rattling the bars of the Iranian cage.