Fear grips Iranian academics as radical groups launch campaign of intimidation

Iranian guests leaving a British embassy reception to mark the Queen's official birthday have been harassed by radical students and security officials in a troubling sign of the mounting tensions with the West.

The incidents on Thursday night followed other officially orchestrated attempts to intimidate Iranians with links to the West, whom some conservatives believe are trying to foment a "soft revolution" against the Islamic regime.

At an earlier demonstration, radical student groups threw eggs, stones and paintballs at the embassy walls and tried to prevent guests entering the large compound in central Tehran. They denounced "artists, politicians and disgusting Iranians and traitors" who planned to attend the event.

Inside, several hundred of the 1,500 invited guests consumed canapés and fruit sherbets in the gardens behind the 19th-century residence. The Iranians included government officials, academics, artists, businessmen and representatives of non-government organisations. There were also foreign diplomats, journalists and members of Iran's British community. A chamber orchestra played on the lawn as frogs croaked in the ornamental pond.

As they left, Iranian guests were brazenly intimidated. A few were physically attacked by demonstrators. Unidentified photographers standing directly in front of the gates took a picture of everybody who left. There were several reports of arrests, police questioning and the confiscation of documents. Guests were eventually bused out by embassy staff. "Oh God, they're taking photographs," said a distinguished Iranian academic who reached the gates after inveighing against recent intimidation tactics. "And everything the Americans are doing is making this situation worse."

The daily Kayhan, whose editor is appointed by Iran's supreme leader, Ayatollah Ali Khamenei, had earlier attacked the reception as a joint Anglo-American project in "psychological war", that aimed to " break the taboo of Iranians communicating with foreigners". Some invited guests said they had been warned not to attend.

Conditions for liberals have deteriorated in recent months as heightened US pressure over the Iranian nuclear programme and events in Iraq have put Iran on a virtual war footing. In liberal circles fear of an increasingly paranoid regime is only matched by despair at US policies that they say provoke further intimidation or create a pretext to crack down.

They highlight last year's vote by Congress to approve $61m (£30m) of funds for "democratisation" in Iran - interpreted by the authorities as code for a "soft revolution". Some $20m of that was earmarked for unnamed projects inside the country, with other large allocations for broadcasting. The US Secretary of State, Condoleezza Rice, has since requested an increase in the overall figure to $75m next year.

The policy has been publicly attacked by such diverse figures as the Nobel peace laureate Shirin Ebadi, the prominent activist Akbar Ganji and the Freedom Movement leader Ebrahim Yazdi as endangering domestic proponents of change. Political prisoners say recent interrogations have focused on how the cash is entering Iran.

Conservative politicians and newspapers have warned against a "colour revolution" such as those in former Soviet republics including Ukraine. They have denounced the establishment of a large US office in Dubai to gather intelligence and promote political change, which has been likened by American officials to the 1930s Riga Station targeting the Soviet Union.

A report last month by ABC News in the US revealed presidential backing for a CIA "black operation" to destabilise Iran. An April investigation by the same network linked the Bush administration to Baluchi militants responsible for several bomb attacks near the Pakistan border. Such reports come amid a huge US military build up in the Persian Gulf, attempts to strangle investment in Iran and the seizure of Iranian personnel in Iraq.

The authorities have responded with a campaign of intimidation, arresting some Iranians who travel to the West, have contact with Western policy organisations or hold dual citizenship. Four Iranian-Americans have recently been charged with "spying" and instigating "a soft revolution". A former senior nuclear official, Hossain Mousavian, was also briefly detained in early May, suggesting even the political elite is vulnerable.

Iranians are now frequently scared of attending conferences abroad, speaking to foreign journalists on record or working in civil society projects. As a result, Iranian voices in the West are increasingly limited to officials such as the firebrand President, Mahmoud Ahmadinejad, and émigré groups bitterly opposed to the Tehran government.

Ugly tactics are also being used on the streets, where a recent campaign against un-Islamic dress was widely interpreted as a political message to discourage dissent. More worryingly, gangsters from rough neighbourhoods have been paraded on television, badly bruised, with lavatory brushes and derogatory placards dangling from their necks, raising the spectre of the 1990s when a campaign against crime ended by targeting political dissidents.