Warning signs of Algerian terror cells as early as 1994
Friday prayers in London, October 1995. Hundreds of worshippers file into a makeshift prayer room at the dilapidated Four Feathers community centre near Baker Street in London and each one in turn is handed a crudely printed newsletter.
The paper Al-Ansar ("The Victorious") glorifies atrocities carried out by "mujahedin", or holy warriors, in Algeria, including a terrorist attack on a passenger train in which scores of people were killed.
Seven years later, the congregation's imam, Abu Qatada, and the newsletter's Algerian editor, Rachid Ramda, are being held in high-security prison cells and Britain's 12,000-strong Algerian population is the focal point of one of the biggest terror alerts mounted in this country.
A decade ago, Algerians were almost unknown in Britain, with only 25 asylum applications from the North African state in 1990. The outbreak of a barbaric civil war in 1992 changed that.
By 1995, the number of Algerians claiming sanctuary had risen to 1,865. Most of those were genuine asylum-seekers, but not all. Among those who became regular visitors to the Four Feathers and to the Finsbury Park mosque in north London was Abu "The Doctor" Doha, who has since been identified as al-Qa'ida's main recruiter in Europe. Abu Doha, now 37, was a senior figure in an Algerian terror group called the Salafist Group for Call and Combat (GSPC).
According to Pierre de Bousquet de Florian, the head of Direction de la Surveillance du Territoire (DST), the French internal security service, Abu Doha's arrest at Heathrow airport in February 2001 as he tried to board a flight to Saudi Arabia came "a little too late". Abu Doha, he said, was the "principal catalyst" in establishing a network of Islamic terrorists in London.
Before the Algerian was arrested, he organised travel for recruits to al-Qa'ida's camps in Chechnya and Afghanistan where training included the production of chemical weapons, such as ricin. The recruits have since formed cells in Europe, financed by fraud and adept at making false travel documents.
London disciples of Abu Qatada and Abu Doha included Djamel Beghal, a French-Algerian arrested for masterminding a plot to blow up the US embassy in Paris, and Zacarias Moussaoui, a French-Moroccan held in America as the "20th hijacker", suspected of planning to take part in the 11 September attacks.
Rabah Kadre, or "Toufik", another British-based Algerian, was arrested on 9 November last year, suspected of planning a terrorist attack on London.
France first expressed concerns at growing levels of Islamic extremism in London as long ago as 1994. Raids that year in Paris on suspected Algerian terrorists traced fax numbers to Finsbury Park and other London addresses.
Britain's long-standing policy of not requiring dissidents to renounce all political activity was seen as a reason why London had become, by the mid-1990s, a haven for Muslim radicals. In May 1995, the Prime Minister, John Major, told Arab ambassadors in London that radical Muslim dissidents who abused British hospitality were "extremely unwelcome". But Abu Doha and Abu Qatada continued to preach. So did the radical ex-mujahedin fighter Abu Hamza at his mosque in Finsbury Park.
As early as January 1996, reports in the British press claimed security sources believed that a Saudi Arabian millionaire called "Oussama-ibn-Laden" (sic) was bankrolling a London group of Algerian Muslim militants. It was claimed the Saudi tycoon, then based in Sudan, was sending cash to Mr Ramda, the editor of Al-Ansar, the paper distributed at the Four Feathers and some London mosques.
Britain's tolerance of such individuals was never fully clear. Some speculated that the intelligence services preferred to have the radicals in London, where their activities could be monitored, rather than drive them underground.
But the effects of such a policy were slow-burning. Shortly before the start of the football World Cup in France in 1998, anti-terrorist officers from Scotland Yard arrested eight Algerians in raids in London. They were believed to be planning attacks on the tournament. Months later, three more Algerians based in London were arrested allegedly preparing to smuggle deadly chemicals to Algeria in tins of baby food.
Since 1998, there has been a fresh surge in Algerian immigration to Britain as people have fled ongoing political violence and a collapsed economy.
Claire Spencer, a North African specialist at the International Institute for Strategic Studies, pointed out that the overwhelming majority of Algerians in Britain were genuine refugees. Millions of Algerians support an Islamist government but not violence, she said. "There has been a breakdown in law and order in Algeria which has made life very difficult for a number of people."
French and British intelligence now work more closely; the Manchester operation followed the December arrest in a Paris suburb of a cell thought to be planning an attack on the Russian embassy.
Abu Doha, meanwhile, is fighting extradition to America. Mr Ramda has spent seven years resisting being sent for trial in France, where he is accused of financing the 1995 Paris Metro bombings. Last summer the law lords quashed an order by the Home Secretary for his extradition. Abu Qatada is being held under emergency terror legislation introduced after the 11 September attacks.
But while they reside at Britain's most secure jail, Belmarsh prison in south London, many of the followers who they called to arms remain at large.