Armed police have arrested 14 men following anti-terror raids in London, including 12 arrests at a restaurant in the Borough area.
Two people were held elsewhere in the city in what police said was an intelligence-led operation.
Police said the arrests were not connected to the alleged transatlantic jet bomb plot or the 7 July attacks.An Islamic school near Tunbridge Wells has also been searched as part of the same operation.
The Jameah Islameah property, on Catt's Hill near Crowborough, East Sussex, is an Islamic teaching facility for boys aged between 11 and 16.
According to its website the 54-acre premises also encourages Islamic groups to "appoint a person from your centre who wishes to serve the community and send them to us to be trained".
It also says these individuals will then become "qualified enough to teach in local Masajeds and Madares". At the time of its last inspection the school only had nine pupils.
Eyewitnesses say the area has now been sealed off and about 100 officers are at the scene.
The BBC's Keith Doyle said the south London restaurant where the 12 arrests were made was a halal Chinese called The Bridge to China Town.
He said the raids came after "months of surveillance into those suspected of recruiting or encouraging others to take part in terrorist activities".
The restaurant was full of people, including children, when around 40 police officers wearing riot gear raided it shortly after 2200 BST on Friday.
Diners were told they were being questioned under the Terrorism Act. Each was asked to give their name and address, after which those arrested were taken away in handcuffs.
Police said the men were arrested under the Terrorism Act 2000 on suspicion of the commission, preparation or instigation of acts of terrorism.
Anti-terrorist officers also carried out raids on a number of addresses in other parts of London, with a search being carried out at an address in the north of the capital.
The restaurant's owner, Mehdi Belyani, 40, said a group of around 15 men and two small boys had come in for dinner at 9pm.
He described them as aged between 25 and 35 and said some were wearing Islamic dress.
"It was surprising actually, because plenty of [police officers] suddenly came in all together. There were more than 50 or 60 of them," he said.
"They suddenly came inside because they were suspicious of some of the customers, and they talked to them."They talked to them [for] more than one hour, two hours. And they arrested some of them.
"So it was obviously surprising for me, my staff, for everyone anyway."
The BBC's security correspondent, Gordon Corera, said the arrests were linked to allegations of "training camps" within the UK for people who want to engage in terrorist acts.
"This involves people suspected of facilitating training activity within the UK which might have allowed others to take part in terrorist activity," he said.
"Here in the UK it's more forms of bonding and getting groups together as well as radicalising those taking part. It's not necessarily military or terrorist training or blowing things up, it's more training in the sense of groups bonding and working together".
Some of the 7 July bombers were suspected of having undertaken this kind of training activity within the UK, although there is no link to those arrested overnight.
A spokeswoman for Home Secretary John Reid said he had been "kept fully informed".
Meanwhile, two men have also been arrested in other anti-terror raids in Manchester but a spokesman for Greater Manchester Police said these arrests were not linked to the London raids.
The pair were detained under the Terrorism Act and three addresses in the Cheetham Hill area are being searched.A spokesman said both arrests followed an operation that took place on 23 August, when one man was held and a house in Elmfield Street in Cheetham Hill was searched.