An Islamic school remains the focus of a police anti-terror investigation today which has seen 14 people arrested in raids.
Officers have been searching the establishment near Crowborough, East Sussex and a large number of residential properties across London since the men were detained overnight on Friday.
It has emerged radical Islamic cleric Abu Hamza – jailed for seven years in February after being convicted of a string of race hate and terror charges - stayed at the school but was asked by staff to leave.
The arrested men, aged from 17 to 48 years, were detained in the capital under the Terrorism Act 2000 after months of surveillance involving Scotland Yard’s Anti-Terrorist branch and MI5.
Some of the men, who are thought to be mainly young British Muslims of Pakistani origin, were detained at a Chinese restaurant in the Borough area of the city.
A Scotland Yard spokesman said the men had been arrested on suspicion of the commission, preparation or instigation of acts of terrorism.
He added that the arrests were not linked to the recent alleged plot to blow up transatlantic airliners or the July 7 bombings in London.
Security sources said the London investigation was focusing on the alleged recruitment and radicalisation of young British Muslims and the facilitation of training for terrorism purposes.
It is not yet clear whether the men were part of one group, or disparate groups who knew each other.
Sources said there was no evidence that any kind of terror attack was imminent and that further arrests by police were not imminent.
The Jameah Islamiyah secondary school being searched by police opened in September 2003 as an independent day school for Muslim boys aged 11 to 16, with annual fees of £1,000.
The establishment in Mark Cross is set within 54 acres and has 100 rooms, including outhouses. Its vast grounds are often used at weekends as a retreat for Muslim families living in London wanting to escape the capital.
Conservative MP Charles Hendry, whose Wealden constituency encompasses the school, visited the establishment twice in the past five years.
He added: “From what I have heard, Abu Hamza and a group did stay there, but they were unco-operative and were asked to leave. That is just from the stories I have heard and I don’t know any more.”
Bilal Patel, the school’s principal, speaking about Hamza, told the Sunday Times: “We advertise in mosques in London for camping breaks in our grounds and he and his group responded.
“When Hamza arrived we were immediately concerned about his strange behaviour. We had no idea what they were doing but we were not happy with it.”
According to its Ofsted report last December, the school had only nine boys on its roll, aged from 12 to 15.
The establishment said in a statement to inspectors that it aimed to “provide a high standard of academic and Islamic education” and to “develop real Islamic morals“.
However, Ofsted inspectors found the school failed to provide a satisfactory education for its pupils, and has significant weaknesses.
A Metropolitan Police spokesman said that the search of school buildings and grounds would continue throughout the day.
“No arrests have been made at the school. It is purely a search operation. The search continues. We cannot speculate on how long it will take. It will take as long as possible,” the spokesman added.