Shock troops of the Iranian Revolution

The Basij is a paramilitary volunteer militia that originally earned its reputation during Iran's war with Iraq in the 1980s.

The Basij is a paramilitary volunteer militia that originally earned its reputation protecting Iran's people during the war with Iraq in the 1980s. Today on the streets the organisation is feared and respected in equal measure. Michael Theodoulou, foreign correspondent, reports When Iraqi forces attacked Iran in 1980, Hossein Fahmideh, 13, left home without his parents' permission, desperate to help repel the invaders. Months later he rolled under an Iraqi tank and yanked the pin out of a grenade. He killed himself, crippled the tank and, the story goes, thwarted a wider enemy advance.

Ayatollah Ruhollah Khomeini, father of Iran's 1979 Islamic revolution, hailed Hossein as "our leader" and proclaimed: "He drank the elixir of martyrdom." Hossein was lionised as a zealous young war hero to inspire others. A 1986 postage stamp commemorated him, while statues and huge murals in Tehran still honour his sacrifice. Hossein had enlisted in the Basij-e-Mustazafin ("Mobilisation of the Deprived"), a paramilitary volunteer militia established by Khomeini in 1979 as a civil defence force. The Basij drew mainly from poor, devout and rural families, enrolling boys under 18, men over 45, and women.

Basij fighters gained fame for enthusiastically leading mass human-wave assaults against the better-armed Iraqis. Many Basij, too young to shave, served as mine-sweepers on what were effectively suicide missions, clearing the way for better equipped and trained Iranian forces. Tens of thousands of Basijis died. Their 1980s generation is respected for defending the homeland against foreign forces. But today's Basij is best known, ingloriously, as the vast and feared paramilitary network that, together with its big brother, the Revolutionary Guard, serves as the regime's enforcers against Iran's supposed enemy within: unarmed fellow Iranians demanding freedom and justice.

The Basij has spearheaded the violent crackdown against those challenging the president Mahmoud Ahmadinejad's "stolen" re-election last June. Sometimes they ram demonstrators in fleets of motorcycles, brandishing clubs, chains and even firearms. Dressed in plain clothes, they also infiltrate unsuspecting crowds before lashing out in their midst. Scores of protesters have been killed since June. Best known is Neda Soltan, a student shot dead during an opposition demonstration days after the elections. Her dying moments, filmed on a mobile phone, were broadcast around the world, making her an instant icon of the opposition and a symbol of the regime's brutality.

Reliable witnesses said she was shot by a Basij militiaman. But the regime crudely attempted to negate her "martyrdom", variously blaming fellow demonstrators, the CIA and agents of Iran's foreign enemies. There will be no statues of Soltan - at least under Iran's current leadership. Shortly before his death last December, Grand Ayatollah Hossein Ali Montazeri, the opposition's spiritual leader, excoriated the Basij. "Why do you beat people?" he demanded. "Because they do not accept what you say? Basij was founded to act within the path of God, not Satan. Isn't it unfortunate to go to hell for the benefit of others?"

At opposition protests, the militiamen are taunted with the chant: "Cannon, tanks and Basijis no longer have an effect." The Basij's fall from grace, in the eyes of many Iranians, began when the war with Iraq ended in 1988. Its members were given a new role as moral vigilantes fronting the drive against liberal tendencies at home - such as women flouting the official dress code. Then, during the 1997 to 2005 reformist presidency of Mohammad Khatami they served as shock troops breaking up pro-reform gatherings and student protests.

The Basij's power grew rapidly after Mr Ahmadinejad, a former Revolutionary Guard, was elected president in 2005. Revolutionary Guard and Basij commanders ordered their foot soldiers to vote for him and he rewarded the affiliated forces generously, enmeshing them deeply in Iran's political and economic structures. Mr Ahmadinejad's cabinet recently passed a motion to expand the Basij's political voice, inviting the militia to become involved with decisions and policies in every ministry. Funding for the Basij last year soared by a spectacular 200 per cent to more than US$500 million (Dh1.8billion).

In 2008, the Basij came under the formal command of the Revolutionary Guard, confirming its evolution from loosely organised Islamic vigilantes into a cohesive, influential force. Precise numbers on Basij membership are not published. Some experts put the force's size at between 400,000 and one million, although Basij commanders claim 11 million members, half of them women. Many are reservists leading mostly normal lives who enlisted for such perks as reserved university places or to secure civil service employment.

The Basij is, however, underpinned by many true believers, steeped in hardline ideology after joining up as pre-teens. The militia is a valuable source of local, nationwide intelligence for the security forces. But its grass-roots base also means the loyalty of many cannot be trusted, especially when they confront protesting friends or neighbours. A morose-looking Basiji at a recent opposition demonstration confided his discomfiture to a middle-aged Tehran man.

"He told me 'I was brought here' and said he was feeling very bad about it." The man, who did not want to be named, added: "Many government organisations just come and ask you to join the Basij and even if you don't want to, you don't dare say no." The bulk of the Basij are involved in reconstruction - building houses, asphalting roads and distributing food, "which is accepted and recognised as a contribution to social well-being, especially in rural areas", said Anoush Ehteshami, an Iran expert at Britain's Durham University.

"But there is an element of the Basij which is now hungry for economic power, muscling into big, big economic projects," Mr Ehteshami said in an interview. "It [the Basij] has also become much more political and that is resented, that is not accepted."