Witness: Westbourne Grove terror raid 'looked planned'
14 October 2013 Last updated at 03:01 BST
Scotland Yard says four men have been arrested in London under the Terrorism Act.
They are being held on suspicion of the commission, preparation or instigation of acts of terrorism.
Alistair Gillies saw one of the arrests, which took place in Westbourne Grove, Bayswater.